Easter called Pascha or Resurrection Sunday, is a festival and holiday commemorating the resurrection of Jesus from the dead, described in the New Testament as having occurred on the third day after his burial following his crucifixion by the Romans at Calvary c. 30 AD. It is the culmination of the Passion of Jesus, preceded by Lent, a 40-day period of fasting and penance. Most Christians refer to the week before Easter as "Holy Week", which contains the days of the Easter Triduum, including Maundy Thursday, commemorating the Maundy and Last Supper, as well as Good Friday, commemorating the crucifixion and death of Jesus. In Western Christianity, Eastertide, or the Easter Season, begins on Easter Sunday and lasts seven weeks, ending with the coming of the 50th day, Pentecost Sunday. In Eastern Christianity, the season of Pascha begins on Pascha and ends with the coming of the 40th day, the Feast of the Ascension. Easter and the holidays that are related to it are moveable feasts which do not fall on a fixed date in the Gregorian or Julian calendars which follow only the cycle of the sun.
The First Council of Nicaea established two rules, independence of the Jewish calendar and worldwide uniformity, which were the only rules for Easter explicitly laid down by the council. No details for the computation were specified, it has come to be the first Sunday after the ecclesiastical full moon that occurs on or soonest after 21 March, but calculations vary. Easter is linked to the Jewish Passover by much of its symbolism, as well as by its position in the calendar. In most European languages the feast is called by the words for passover in those languages. Easter customs vary across the Christian world, include sunrise services, exclaiming the Paschal greeting, clipping the church, decorating Easter eggs; the Easter lily, a symbol of the resurrection, traditionally decorates the chancel area of churches on this day and for the rest of Eastertide. Additional customs that have become associated with Easter and are observed by both Christians and some non-Christians include egg hunting, the Easter Bunny, Easter parades.
There are various traditional Easter foods that vary regionally. The modern English term Easter, cognate with modern Dutch ooster and German Ostern, developed from an Old English word that appears in the form Ēastrun, -on, or -an; the most accepted theory of the origin of the term is that it is derived from the name of an Old English goddess mentioned by the 7th to 8th-century English monk Bede, who wrote that Ēosturmōnaþ was an English month, corresponding to April, which he says "was once called after a goddess of theirs named Ēostre, in whose honour feasts were celebrated in that month". In Latin and Greek, the Christian celebration was, still is, called Pascha, a word derived from Aramaic פסחא, cognate to Hebrew פֶּסַח; the word denoted the Jewish festival known in English as Passover, commemorating the Jewish Exodus from slavery in Egypt. As early as the 50s of the 1st century, writing from Ephesus to the Christians in Corinth, applied the term to Christ, it is unlikely that the Ephesian and Corinthian Christians were the first to hear Exodus 12 interpreted as speaking about the death of Jesus, not just about the Jewish Passover ritual.
In most of the non-English speaking world, the feast is known by names derived from Greek and Latin Pascha. Pascha is a name by which Jesus himself is remembered in the Orthodox Church in connection with his resurrection and with the season of its celebration; the New Testament states that the resurrection of Jesus, which Easter celebrates, is one of the chief tenets of the Christian faith. The resurrection established Jesus as the powerful Son of God and is cited as proof that God will righteously judge the world. For those who trust in Jesus' death and resurrection, "death is swallowed up in victory." Any person who chooses to follow Jesus receives "a new birth into a living hope through the resurrection of Jesus Christ from the dead". Through faith in the working of God those who follow Jesus are spiritually resurrected with him so that they may walk in a new way of life and receive eternal salvation. Easter is linked to Passover and the Exodus from Egypt recorded in the Old Testament through the Last Supper and crucifixion of Jesus that preceded the resurrection.
According to the New Testament, Jesus gave the Passover meal a new meaning, as in the upper room during the Last Supper he prepared himself and his disciples for his death. He identified the matzah and cup of wine as his body soon to be sacrificed and his blood soon to be shed. Paul states, "Get rid of the old yeast that you may be a new batch without yeast—as you are. For Christ, our Passover lamb, has been sacrificed"; the first Christians and Gentile, were aware of the Hebrew calendar. Jewish Christians, the first to celebrate the resurrection of Jesus, timed the observance in relation to Passover. Direct evidence for a more formed Christian festival of Pascha begins to appear in the mid-2nd century; the earliest extant primary source referring to East
Aquitaine, archaic Guyenne/Guienne, is a historical region of France and a former administrative region of the country. Since 1 January 2016 it has been part of the region Nouvelle-Aquitaine, it is situated in the south-western part of Metropolitan France, along the Atlantic Ocean and the Pyrenees mountain range on the border with Spain. It is composed of the five departments of Dordogne, Lot-et-Garonne, Pyrénées-Atlantiques and Gironde. In the Middle Ages, Aquitaine was a duchy, whose boundaries fluctuated considerably. There are traces of human settlement by prehistoric peoples in the Périgord, but the earliest attested inhabitants in the south-west were the Aquitani, who were not proper Celtic people, but more akin to the Iberians. Although a number of different languages and dialects were in use in the area during ancient times, it is most that the prevailing language of Aquitaine during the late pre-historic to Roman period was an early form of the Basque language; this has been demonstrated by various Aquitanian names and words that were recorded by the Romans, which are easily readable as Basque.
Whether this Aquitanian language was a remnant of a Vasconic language group that once extended much farther, or it was limited to the Aquitaine/Basque region is not known. One reason the language of Aquitaine is important is because Basque is the last surviving non-Indo-European language in western Europe and it has had some effect on the languages around it, including Spanish and, to a lesser extent, French; the original Aquitania at the time of Caesar's conquest of Gaul included the area bounded by the Garonne River, the Pyrenees and the Atlantic Ocean. The name may stem from Latin'aqua', maybe derived from the town "Aquae Augustae", "Aquae Tarbellicae" or just "Aquis" or as a more general geographical feature. Under Augustus' Roman rule, since 27 BC the province of Aquitania was further stretched to the north to the River Loire, thus including proper Gaul tribes along with old Aquitani south of the Garonne within the same region. In 392, the Roman imperial provinces were restructured as Aquitania Prima, Aquitania Secunda and Aquitania Tertia, better known as Novempopulania in the south-west.
Accounts of Aquitania during the Early Middle Ages are a blur, lacking precision, but there was much unrest. The Visigoths were called into Gaul as foederati, they established themselves as the de facto rulers in south-west Gaul as central Roman rule collapsed. Visigoths established their capital in Toulouse. In 507, they were expelled south to Hispania after their defeat in the Battle of Vouillé by the Franks, who became the new rulers in the area to the south of the Loire; the Roman Aquitania Tertia remained in place as Novempopulania, where a duke was appointed to hold a grip over the Basques. These dukes were quite detached from central Frankish overlordship, sometimes governing as independent rulers with strong ties to their kinsmen south of the Pyrenees; as of 660, the foundations for an independent Aquitaine/Vasconia polity were established by the duke Felix of Aquitaine, a magnate from Toulouse of Gallo-Roman stock. Despite its nominal submission to the Merovingians, the ethnic make-up of new realm Aquitaine wasn't Frankish, but Gallo-Roman north of the Garonne and main towns and Basque south of the Garonne.
A united Basque-Aquitanian realm reached its heyday under Odo the Great's rule. In 721, the Aquitanian duke fended Umayyad troops off at Toulouse, but in 732, an Umayyad expedition commanded by Abdul Rahman Al Ghafiqi defeated Odo next to Bordeaux, went on to loot its way up to Poitiers. Odo was required to pledge allegiance to the Frankish Charles Martel in exchange for help against the advancing Arabic forces. Basque-Aquitanian self-rule temporarily came to a halt in 768 after the assassination of Waifer. In 781, Charlemagne decided to proclaim his son Louis King of Aquitaine within the Carolingian Empire, ruling over a realm comprising the Duchy of Aquitaine and the Duchy of Vasconia He suppressed various Basque uprisings venturing into the lands of Pamplona past the Pyrenees after ravaging Gascony, with a view to imposing his authority in the Vasconia to south of Pyrenees. According to his biography, he achieved everything he wanted and after staying overnight in Pamplona, on his way back his army was attacked in Roncevaux in 812, but narrowly escaped an engagement at the Pyrenean passes.
Seguin, count of Bordeaux and Duke of Vasconia, seemed to have attempted a detachment from the Frankish central authority on Charlemagne's death. The new emperor Louis the Pious reacted by removing him from his capacity, which stirred the Basques into rebellion; the king in turn sent his troops to the territory, obtaining their submission in two campaigns and killing the duke, while his family crossed the Pyrenees and continued to foment risings against Frankish power. In 824, the 2nd Battle of Roncevaux took place, in which counts Aeblus and Aznar, Frankish vassals from the Duchy of Vasconia sent by the new King of Aquitaine, were captured by the joint forces of Iñigo Arista and the Banu Qasi. Before Pepin's death, emperor Louis had appointed a new king in 832, his son Charles the Bald, while the Aquitanian lords elected Pepin II as king; this struggle for control of the kingdom led to
Christianity is an Abrahamic religion based on the life and teachings of Jesus of Nazareth, as described in the New Testament. Its adherents, known as Christians, believe that Jesus Christ is the Son of God and savior of all people, whose coming as the Messiah was prophesied in the Old Testament. Depending on the specific denomination of Christianity, practices may include baptism, prayer, confirmation, burial rites, marriage rites and the religious education of children. Most denominations hold regular group worship services. Christianity developed during the 1st century CE as a Jewish Christian sect of Second Temple Judaism, it soon attracted Gentile God-fearers, which lead to a departure from Jewish customs, the establishment of Christianity as an independent religion. During the first centuries of its existence Christianity spread throughout the Roman Empire, to Ethiopia and some parts of Asia. Constantine the Great decriminalized it via the Edict of Milan; the First Council of Nicaea established a uniform set of beliefs across the Roman Empire.
By 380, the Roman Empire designated Christianity as the state religion. The period of the first seven ecumenical councils is sometimes referred to as the Great Church, the united full communion of the Roman Catholic Church, Eastern Orthodox Church, Oriental Orthodoxy, before their schisms. Oriental Orthodoxy split after the Council of Chalcedon over differences in Christology; the Eastern Orthodox Church and the Catholic Church separated in the East–West Schism over the authority of the Pope. In 1521, Protestants split from the Catholic Church in the Protestant Reformation over Papal primacy, the nature of salvation, other ecclesiological and theological disputes. Following the Age of Discovery, Christianity was spread into the Americas, sub-Saharan Africa, the rest of the world via missionary work and colonization. There are 2.3 billion Christians in the world, or 31.4% of the global population. Today, the four largest branches of Christianity are the Catholic Church, the Eastern Orthodox Church and Oriental Orthodoxy.
Christianity and Christian ethics have played a prominent role in the development of Western civilization around Europe during late antiquity and the Middle Ages. In the New Testament, the names by which the disciples were known among themselves were "brethren", "the faithful", "elect", "saints" and "believers". Early Jewish Christians referred to themselves as'The Way' coming from Isaiah 40:3, "prepare the way of the Lord." According to Acts 11:26, the term "Christian" was first used in reference to Jesus's disciples in the city of Antioch, meaning "followers of Christ," by the non-Jewish inhabitants of Antioch. The earliest recorded use of the term "Christianity" was by Ignatius of Antioch, in around 100 AD. While Christians worldwide share basic convcitions, there are differences of interpretations and opinions of the Bible and sacred traditions on which Christianity is based. Concise doctrinal statements or confessions of religious beliefs are known as creeds, they began as baptismal formulae and were expanded during the Christological controversies of the 4th and 5th centuries to become statements of faith.
The Apostles' Creed is the most accepted statement of the articles of Christian faith. It is used by a number of Christian denominations for both liturgical and catechetical purposes, most visibly by liturgical churches of Western Christian tradition, including the Latin Church of the Catholic Church, Lutheranism and Western Rite Orthodoxy, it is used by Presbyterians and Congregationalists. This particular creed was developed between the 9th centuries, its central doctrines are those of God the Creator. Each of the doctrines found in this creed can be traced to statements current in the apostolic period; the creed was used as a summary of Christian doctrine for baptismal candidates in the churches of Rome. Its main points include: Belief in God the Father, Jesus Christ as the Son of God, the Holy Spirit The death, descent into hell and ascension of Christ The holiness of the Church and the communion of saints Christ's second coming, the Day of Judgement and salvation of the faithful; the Nicene Creed was formulated in response to Arianism, at the Councils of Nicaea and Constantinople in 325 and 381 and ratified as the universal creed of Christendom by the First Council of Ephesus in 431.
The Chalcedonian Definition, or Creed of Chalcedon, developed at the Council of Chalcedon in 451, though rejected by the Oriental Orthodox churches, taught Christ "to be acknowledged in two natures, unchangeably, inseparably": one divine and one human, that both natures, while perfect in themselves, are also united into one person. The Athanasian Creed, received in the Western Church as having the same status as the Nicene and Chalcedonian, says: "We worship one God in Trinity, Trinity in Unity. Many evangelical Protestants reject creeds as definitive statements of faith while agreeing with some or all of the substance of the creeds. Most Baptists do not use creeds "in that they have not sought to establish binding
Coptic Orthodox Church of Alexandria
The Coptic Orthodox Church of Alexandria is an Oriental Orthodox Christian church based in Egypt and the Middle East. The head of the Church and the See of Alexandria is the Patriarch of Alexandria on the Holy See of Saint Mark, who carries the title of Coptic Pope; the See of Alexandria is titular, today the Coptic Pope presides from Saint Mark's Coptic Orthodox Cathedral in the Abbassia District in Cairo. The church follows the Alexandrian Rite for its liturgy and devotional patrimony. With 18–22 million members worldwide, whereof about 15 to 20 million are in Egypt, it is the country's largest Christian church. According to its tradition, the Coptic Church was established by Saint Mark, an apostle and evangelist, during the middle of the 1st century. Due to disputes concerning the nature of Christ, it split from the rest of the Christendom after the Council of Chalcedon in AD 451, resulting in a rivalry with the Byzantine Orthodox Church. In the 4–7th centuries the Coptic Church expanded due to the Christianization of the Aksumite empire and of two of the three Nubian kingdoms and Alodia, while the third Nubian kingdom, recognized the Coptic patriarch after being aligned to the Byzantine Orthodox Church.
After AD 639 Egypt was ruled by its Islamic conquerors from Arabia, the treatment of the Coptic Christians ranged from tolerance to open persecution. In the 12th century, the church relocated its seat from Alexandria to Cairo; the same century saw the Copts become a religious minority. During the 14th and 15th centuries, Nubian Christianity was supplanted by Islam. In 1959, the Ethiopian Orthodox Tewahedo Church was granted independence; this was extended to the Eritrean Orthodox Tewahedo Church in 1998 following the successful Eritrean War of Independence from Ethiopia. Since the Arab Spring in 2011, the Copts have been suffering increased religious discrimination and violence; the Egyptian Church is traditionally believed to be founded by St Mark at around AD 42, regards itself as the subject of many prophecies in the Old Testament. Isaiah the prophet, in Chapter 19, Verse 19 says "In that day there will be an altar to the LORD in the midst of the land of Egypt, a pillar to the LORD at its border".
The first Christians in Egypt were common people. There were Alexandrian Jewish people such as Theophilus, whom Saint Luke the Evangelist addresses in the introductory chapter of his gospel; when the church was founded by Saint Mark during the reign of the Roman emperor Nero, a great multitude of native Egyptians embraced the Christian faith. Christianity spread throughout Egypt within half a century of Saint Mark's arrival in Alexandria, as is clear from the New Testament writings found in Bahnasa, in Middle Egypt, which date around the year AD 200, a fragment of the Gospel of John, written in Coptic, found in Upper Egypt and can be dated to the first half of the 2nd century. In the 2nd century, Christianity began to spread to the rural areas, scriptures were translated into the local languages, namely Coptic; the Coptic language is a universal language used in Coptic churches in every country. It uses Greek letters. Many of the hymns in the liturgy have been passed down for several thousand years.
The language is used to preserve Egypt's original language, banned by the Arab invaders, who ordered Arabic to be used instead. Some examples of these hymns are Coptic: translit. Ep.ouro, lit.'The King',Coptic: Ⲉⲕⲥⲙⲁⲣⲱⲟⲩⲧ, translit. Ek.esmaro'oot, lit.' Blessed', Coptic: Ⲧⲁⲓϣⲟⲩⲣⲏ, translit. Tai.shouri, lit.'This Censer', many more. The Catechetical School of Alexandria is the oldest catechetical school in the world. St. Jerome records. Around AD 190, under the leadership of the scholar Pantanaeus, the school of Alexandria became an important institution of religious learning, where students were taught by scholars such as Athenagoras, Clement and the native Egyptian Origen, considered the father of theology and, active in the field of commentary and comparative Biblical studies. Many scholars such as Jerome visited the school of Alexandria to exchange ideas and to communicate directly with its scholars; the scope of this school was not limited to theological subjects. The question-and-answer method of commentary began there, 15 centuries before Braille, wood-carving techniques were in use there by blind scholars to read and write.
The Theological college of the catechetical school was re-established in 1893. The new school has campuses in Ireland, New Jersey, Los Angeles, where Coptic priests-to-be and other qualified men and women are taught among other subjects Christian theology, the Coptic language and art – including chanting, music and tapestry. Many Egyptian Christians went to the desert during the 3rd century, remained there to pray and work and dedicate their lives to seclusion and worship of God; this was the beginning of the monastic movement, organized by Anthony the Great, Saint Paul of Thebes, the world's first anchorite, Saint Macarius the Great and Saint Pachomius the Cenobite in the 4th century. Christian monasticism was born in Egypt and was instrumental in the formation of the Coptic Orthodox Church character of submission and humility, thanks to the teachings and writings of the Great Fathers of Egypt's Deserts. By the end of the 5th century, the
A bishop is an ordained, consecrated, or appointed member of the Christian clergy, entrusted with a position of authority and oversight. Within the Catholic Church, Eastern Orthodox, Oriental Orthodox, Anglican, Old Catholic and Independent Catholic churches and in the Assyrian Church of the East, bishops claim apostolic succession, a direct historical lineage dating back to the original Twelve Apostles. Within these churches, bishops are seen as those who possess the full priesthood and can ordain clergy – including another bishop; some Protestant churches including the Lutheran and Methodist churches have bishops serving similar functions as well, though not always understood to be within apostolic succession in the same way. One, ordained deacon and bishop is understood to hold the fullness of the priesthood, given responsibility by Christ to govern and sanctify the Body of Christ, members of the Faithful. Priests and lay ministers cooperate and assist their bishops in shepherding a flock.
The term epískopos, meaning "overseer" in Greek, the early language of the Christian Church, was not from the earliest times distinguished from the term presbýteros, but the term was clearly used in the sense of the order or office of bishop, distinct from that of presbyter in the writings attributed to Ignatius of Antioch.. The earliest organization of the Church in Jerusalem was, according to most scholars, similar to that of Jewish synagogues, but it had a council or college of ordained presbyters. In Acts 11:30 and Acts 15:22, we see a collegiate system of government in Jerusalem chaired by James the Just, according to tradition the first bishop of the city. In Acts 14:23, the Apostle Paul ordains presbyters in churches in Anatolia; the word presbyter was not yet distinguished from overseer, as in Acts 20:17, Titus 1:5–7 and 1 Peter 5:1. The earliest writings of the Apostolic Fathers, the Didache and the First Epistle of Clement, for example, show the church used two terms for local church offices—presbyters and deacon.
In Timothy and Titus in the New Testament a more defined episcopate can be seen. We are told that Paul had left Timothy in Titus in Crete to oversee the local church. Paul commands Titus to exercise general oversight. Early sources are unclear but various groups of Christian communities may have had the bishop surrounded by a group or college functioning as leaders of the local churches; the head or "monarchic" bishop came to rule more and all local churches would follow the example of the other churches and structure themselves after the model of the others with the one bishop in clearer charge, though the role of the body of presbyters remained important. As Christendom grew, bishops no longer directly served individual congregations. Instead, the Metropolitan bishop appointed priests to minister each congregation, acting as the bishop's delegate. Around the end of the 1st century, the church's organization became clearer in historical documents. In the works of the Apostolic Fathers, Ignatius of Antioch in particular, the role of the episkopos, or bishop, became more important or, rather was important and being defined.
While Ignatius of Antioch offers the earliest clear description of monarchial bishops he is an advocate of monepiscopal structure rather than describing an accepted reality. To the bishops and house churches to which he writes, he offers strategies on how to pressure house churches who don't recognize the bishop into compliance. Other contemporary Christian writers do not describe monarchial bishops, either continuing to equate them with the presbyters or speaking of episkopoi in a city. "Blessed be God, who has granted unto you, who are yourselves so excellent, to obtain such an excellent bishop." — Epistle of Ignatius to the Ephesians 1:1 "and that, being subject to the bishop and the presbytery, ye may in all respects be sanctified." — Epistle of Ignatius to the Ephesians 2:1 "For your justly renowned presbytery, worthy of God, is fitted as to the bishop as the strings are to the harp." — Epistle of Ignatius to the Ephesians 4:1 "Do ye, beloved, be careful to be subject to the bishop, the presbyters and the deacons."
— Epistle of Ignatius to the Ephesians 5:1 "Plainly therefore we ought to regard the bishop as the Lord Himself" — Epistle of Ignatius to the Ephesians 6:1. "your godly bishop" — Epistle of Ignatius to the Magnesians 2:1. "the bishop presiding after the likeness of God and the presbyters after the likeness of the council of the Apostles, with the deacons who are most dear to me, having been entrusted with the diaconate of Jesus Christ" — Epistle of Ignatius to the Magnesians 6:1. "Therefore as the Lord did nothing without the Father, either by Himself or by the Apostles, so neither do ye anything without the bishop and the presbyters." — Epistle of Ignatius to the Magnesians 7:1. "Be obedient to the bishop and to one another, as Jesus Christ was to the Father, as the Apostles were to Christ and to the Father, that there may be union both of flesh and of spirit." — Epistle of Ignatius to the Magnesians 13:2. "In like manner let all men respe
Chronology is the science of arranging events in their order of occurrence in time. Consider, for example, the use of a timeline or sequence of events, it is "the determination of the actual temporal sequence of past events". Chronology is a part of periodization, it is a part of the discipline of history including earth history, the earth sciences, study of the geologic time scale. Chronology is the science of locating historical events in time, it relies upon chronometry, known as timekeeping, historiography, which examines the writing of history and the use of historical methods. Radiocarbon dating estimates the age of living things by measuring the proportion of carbon-14 isotope in their carbon content. Dendrochronology estimates the age of trees by correlation of the various growth rings in their wood to known year-by-year reference sequences in the region to reflect year-to-year climatic variation. Dendrochronology is used in turn as a calibration reference for radiocarbon dating curves.
The familiar terms calendar and era concern two complementary fundamental concepts of chronology. For example, during eight centuries the calendar belonging to the Christian era, which era was taken in use in the 8th century by Bede, was the Julian calendar, but after the year 1582 it was the Gregorian calendar. Dionysius Exiguus was the founder of that era, nowadays the most widespread dating system on earth. An epoch is the date. Ab Urbe condita is Latin for "from the founding of the City", traditionally set in 753 BC, it was used to identify the Roman year by a few Roman historians. Modern historians use it much more than the Romans themselves did. Before the advent of the modern critical edition of historical Roman works, AUC was indiscriminately added to them by earlier editors, making it appear more used than it was, it was used systematically for the first time only about the year 400, by the Iberian historian Orosius. Pope Boniface IV, in about the year 600, seems to have been the first who made a connection between these this era and Anno Domini.
Dionysius Exiguus’ Anno Domini era was extended by Bede to the complete Christian era. Ten centuries after Bede, the French astronomers Philippe de la Hire and Jacques Cassini, purely to simplify certain calculations, put the Julian Dating System and with it an astronomical era into use, which contains a leap year zero, which precedes the year 1. While of critical importance to the historian, methods of determining chronology are used in most disciplines of science astronomy, geology and archaeology. In the absence of written history, with its chronicles and king lists, late 19th century archaeologists found that they could develop relative chronologies based on pottery techniques and styles. In the field of Egyptology, William Flinders Petrie pioneered sequence dating to penetrate pre-dynastic Neolithic times, using groups of contemporary artefacts deposited together at a single time in graves and working backwards methodically from the earliest historical phases of Egypt; this method of dating is known as seriation.
Known wares discovered at strata in sometimes quite distant sites, the product of trade, helped extend the network of chronologies. Some cultures have retained the name applied to them in reference to characteristic forms, for lack of an idea of what they called themselves: "The Beaker People" in northern Europe during the 3rd millennium BCE, for example; the study of the means of placing pottery and other cultural artifacts into some kind of order proceeds in two phases and typology: Classification creates categories for the purposes of description, typology seeks to identify and analyse changes that allow artifacts to be placed into sequences. Laboratory techniques developed after mid-20th century helped revise and refine the chronologies developed for specific cultural areas. Unrelated dating methods help reinforce a chronology, an axiom of corroborative evidence. Ideally, archaeological materials used for dating a site should complement each other and provide a means of cross-checking. Conclusions drawn from just one unsupported technique are regarded as unreliable.
The fundamental problem of chronology is to synchronize events. By synchronizing an event it becomes possible to relate it to the current time and to compare the event to other events. Among historians, a typical need to is to synchronize the reigns of kings and leaders in order to relate the history of one country or region to that of another. For example, the Chronicon of Eusebius is one of the major works of historical synchronism; this work has two sections. The first contains narrative chronicles of nine different kingdoms: Chaldean, Median, Persian, Greek, Peloponnesian and Roman; the second part is a long table synchronizing the events from each of the nine kingdoms in parallel columns. The adjacent image shows two pages from the second section. By comparing the parallel columns, the reader can determine which events were contemporaneous, or how many years separated two different events. To place all the events on the same time scale, Eusebius used an Anno Mundi era, meaning that events were dated from the supposed beginning of t
For astronomy and calendar studies, the Metonic cycle or Enneadecaeteris is a period of close to 19 years, nearly a common multiple of the solar year and the synodic month. The Greek astronomer Meton of Athens observed that a period of 19 years is exactly equal to 235 synodic months and, rounded to full days, counts 6,940 days; the difference between the two periods is only a few hours, depending on the definition of the year. Considering a year to be 1⁄19 of this 6,940-day cycle gives a year length of 365 + 1⁄4 + 1⁄76 days, about 11 days more than 12 synodic months. To keep a 12-month lunar year in pace with the solar year, an intercalary 13th month would have to be added on seven occasions during the nineteen-year period; when Meton introduced the cycle around 432 BC, it was known by Babylonian astronomers. A mechanical computation of the cycle is built into the Antikythera mechanism; the cycle was used in the Babylonian calendar, ancient Chinese calendar systems and the medieval computus.
It regulates the 19-year cycle of intercalary months of the modern Hebrew calendar. The start of the Metonic cycle depends on. At the time of Meton, axial precession had not yet been discovered, he could not distinguish between sidereal years and tropical years. Most calendars, like the used Gregorian calendar, are based on the tropical year and maintain the seasons at the same calendar times each year. Nineteen tropical years are about two hours shorter than 235 synodic months; the Metonic cycle's error is, one full day every 219 years, or 12.4 parts per million. 19 tropical years = 6,939.602 days. 235 synodic months = 6,939.688 days. 254 sidereal months = 6,939.702 days. 255 draconic months = 6,939.1161 days. Note that the 19-year cycle is close to 255 draconic months, so it is an eclipse cycle, which lasts only for about 4 or 5 recurrences of eclipses; the Octon is 1⁄5 of a Metonic cycle, it recurs about 20 to 25 cycles. This cycle seems to be a coincidence; the periods of the Moon's orbit around the Earth and the Earth's orbit around the Sun are believed to be independent, not to have any known physical resonance.
An example of a non-coincidental cycle is the orbit of Mercury, with its 3:2 spin-orbit resonance. A lunar year of 12 synodic months is about 354 days 11 days short of the "365-day" solar year. Therefore, for a lunisolar calendar, every 2 to 3 years there is a difference of more than a full lunar month between the lunar and solar years, an extra month needs to be inserted; the Athenians seem not to have had a regular means of intercalating a 13th month. Meton's discovery made it possible to propose a regular intercalation scheme; the Babylonians seem to have introduced this scheme around 500 BC, thus well before Meton. Traditionally, for the Babylonian and Hebrew lunisolar calendars, the years 3, 6, 8, 11, 14, 17, 19 are the long years of the Metonic cycle; this cycle, which can be used to predict eclipses, forms the basis of the Greek and Hebrew calendars, is used for the computation of the date of Easter each year. The Babylonians applied the 19-year cycle since the late sixth century BC; as they measured the moon's motion against the stars, the 235:19 relationship may have referred to sidereal years, instead of tropical years as it has been used for various calendars.
According to Livy, the king of Rome Numa Pompilius inserted intercalary months in such a way that in the twentieth year the days should fall in with the same position of the sun from which they had started. As the twentieth year takes place nineteen years after the first year, this seems to indicate that the Metonic cycle was applied to Numa's calendar. Apollo was said to have visited the Hyperboreans once every 19 years at the high point of the cycle; the Runic calendar is a perpetual calendar based on the 19-year-long Metonic cycle. Known as a Rune staff or Runic Almanac, it appears to have been a medieval Swedish invention; this calendar does not rely on knowledge of the duration of the tropical year or of the occurrence of leap years. It is set at the beginning of each year by observing the first full moon after the winter solstice; the oldest one known, the only one from the Middle Ages, is the Nyköping staff, believed to date from the 13th century. The Bahá'í calendar, established during the middle of the 19th century, is based on cycles of 19 years.
The Metonic cycle is related to two less accurate subcycles: 8 years = 99 lunations to within 1.5 days, i.e. an error of one day in 5 years. By combining appropriate numbers of 11-year and 19-year periods, it is possible to generate more accurate cycles. For example, simple arithmetic shows that: 687 tropical years; this gives an error of only about half an hour in 687 years, although this is subject to secular variation in the length of the tropical year and the lunation. Meton of Athens