In Slavic mythology, Perun is the highest god of the pantheon and the god of sky, lightning, rain, war and oak trees. His other attributes were fire, wind, eagle, firmament and carts, war, he was first associated with weapons made of stone and with those of metal. Of all historic records describing Slavic gods, those mentioning Perun are the most numerous; as early as the 6th century, he was mentioned in De Bello Gothico, a historical source written by the Eastern Roman historian Procopius. A short note describing beliefs of a certain South Slavic tribe states they acknowledge that one god, creator of lightning, is the only lord of all: to him do they sacrifice an ox and all sacrificial animals. While the name of the god is not mentioned here explicitly, 20th century research has established beyond doubt that the god of thunder and lightning in Slavic mythology is Perun. To this day the word perun in a number of Slavic languages means "thunder," or "lightning bolt"; the Primary Chronicle relates that in the year 6415 prince Oleg made a peace treaty with the Byzantine Empire and by taking his men to the shrines and swearing by their weapons and by their god Perun, by Volos, the god of cattle, they confirmed the treaty.
We find the same form of confirmation of a peace treaty by prince Igor in 945. In 980, when prince Vladimir the Great came to the throne of Kiev, he erected statues of five pagan gods in front of his palace which he soon thereafter discarded after his Christianization in 988. Perun was chief among these, represented with a golden moustache. Vladimir's uncle Dobrinja had a shrine of Perun established in his city of Novgorod. After the Christianization of Kievan Rus, this place became a monastery, quite remarkably, continued to bear the name of Perun. Perun is not mentioned directly in any of the records of Western Slavic traditional religion, but a reference to him is made in a short note in Helmold's Chronica Slavorum, written in the latter half of the 12th century, which states that Slavic tribes though they worship many various gods, all agree there is a supreme god in heaven which rules over all other on earth; this could be a reference to Perun, but since he is not named, nor any of his chief attributes mentioned, we cannot be certain.
Moreover, the name of Perun is commonly found in Southern Slavic toponymy. The Bulgarian and Macedonian people believe that the name of the Bulgarian mountain Pirin, one of the highest mountains of the Balkan Peninsula, was named after Perun. Perun is the name of the hill in Podstrana next to Split, Croatia. There are places called: Perun, Perunovac, Perunička Glava, Peruni Vrh, Perunja Ves, Peruna Dubrava, Perunuša, Perušice and Perutovac; the word "Pero" means the names of mountains and cities could refer to poultry. These names today represent mountain tops, but in medieval times, large oaks, sacred groves and entire villages or citadels were named Perun. Among South Slavs, a mountain plant Iris germanica is known in folklore as perunika and sometimes as bogisha, was believed to grow from ground, struck by lightning; the Serbian surname Peruničić and the Macedonian Перуновски are derived from Perun. The Bulgarian people believe that the name of city Pernik is thought to have originated from that of Slavic god Perun with the Slavic placename suffix –nik added, was first mentioned in the 9th century.
The medieval town was a key Bulgarian stronghold during Bulgarian tsar Samuil's wars against the Byzantine Empire in the 11th century, when it was governed by the local noble Krakra of Pernik, withstanding Byzantine sieges a number of times. Some places in Central Europe named after Perun are the villages of Parndorf and Pernitz in the Parndorf Plain, Perná in Moravia, Beroun in Bohemia, Pernek in Slovakia. Perun is correlated with the near-identical Perkūnas/Pērkons from Baltic mythology, suggesting either a common derivative of the Proto-Indo European thunder god, or that one of these cultures borrowed the deity from the other; the root *perkwu probably meant oak, but in Proto-Slavic this evolved into per- meaning "to strike, to slay". The Lithuanian word "Perkūnas" has two meanings: "thunder" and the name of the god of thunder and lightning. Artifacts and toponyms show the presence of the cult of Perun among all Slavic and Ugro-Finnic peoples. Perun was related to an archaic form of astronomy – the Pole star was called Perun's eye and countless Slavic and Hungarian astronomers continued this tradition – most known ones are Nicolaus Copernicus, Franz Xaver von Zach.
In Slavic mythology, much like in Norse and Baltic mythologies, the world was represented by a sacred tree an oak, whose branches and trunk represented the living world of heavens and mortals, whilst its roots represented the underworld, i.e. the realm of the dead. Perun was the ruler of the living world and earth, was symbolised by an eagle sitting on the top of the tallest branch of the sacred tree, from which he kept watch over the entire world. Deep down in the roots of the tree was the place of his opponent, symbolised by a serpent or a dragon: this was Veles, watery god of the underworld, who continually provoked Perun by creeping up f
Mammes of Caesarea
Saint Mammes of Caesarea is a child-martyr of the 3rd century. He was martyred at Caesarea, his parents and Rufina, were martyred. Born in prison to parents, jailed because they were Christian, Mammes became an orphan when his parents were executed. After his parents' death, Mammes was raised by a rich widow named Ammia, who died when Mammes was 15 years old. According to legend, Mammes was tortured for his faith by the governor of Caesarea and was sent before the Roman Emperor Aurelian, who tortured him again; the Mammes legend states that an angel liberated him and ordered him to hide himself on a mountain near Caesarea. Mammes was thrown to the lions, but managed to make the beasts docile, he preached to animals in the fields, a lion remained with him as companion. Accompanied by the lion, he visited Duke Alexander, he was struck in the stomach with a trident. Bleeding, Mammes dragged himself to a spot near a theater before his soul was carried into heaven by angels; the center of his cult was situated at Caesarea before shifting to Langres when his relics were brought there.
The Cathédrale Saint-Mammès, in Langres, is dedicated to him. Mammes is the chief patron of the diocese. Saint Mammes is a popular saint in Lebanon with many churches and convents named in his honor, he is the patron saint of Deir Mimas in Lebanon, where the town celebrates the feast of Saint Mamas on September 15. Grand festivities are organized each year to honor the town's patron saint; the town has an orthodox monastery overlooking the Litani valley of Deirmimas named after the saint in addition to a Melkite catholic church located inside the village named after Saint Mammes. Mammes is honored in Kfarhata, adjacent to Zgharta; the Church of Saint Mamas Church in Ehden was built in 749 A. D. and is one of the oldest Maronite Catholic churches in Lebanon. Lebanon is home to the Saint Mamas Church of Baabdat, built in the 16th century. Another Maronite Lebanese monastery called Dayr Mar Mamas is being restored by the towns folks of the rural village of Bechaaleh located in the district of Batroun in the north of Lebanon.
In Cyprus, Mammes is popularly known as a poor hermit. According to local legend, he was a hermit living in poor circumstances, when the authorities tried to tax him, he evaded them. Soldiers were sent out and captured him, but on the way back to town, Mammes saw a lion attacking a lamb, escaped the soldiers, saved the lamb, jumped on the lion's back, rode it into town, his bravery earned him exemption from taxation. St. Mamas Monastery is the third most important place of worship for the Greek Orthodox in Cyprus after St. Barnabas tomb at Famagusta and Apostolos Andreas Monastery at Karpasia. There are numerous churches dedicated to Mammes of Caesarea in Greece and there are villages in Greece named Agios Mamas after him in Chalkidiki and Laconia. Pilgrims on their way to Santiago de Compostela diffused his cult into Spain. A statue depicting Mammes and a lion can be found in the Casa de la Misericordia in Bilbao, once the convent of San Mamés and whose current chapel holds an alleged relic of the saint, a piece of bone from his craneum.
The stadium, home to the Athletic Club de Bilbao is called San Mamés Stadium, players of that club are called the "lions of San Mamés" because their stadium was built near these premises. His head is said to rest in the parish church of Santa María Magdalena in Zaragoza. An alternative legend states. At Tábara in Spain, he is venerated alongside Saint Blaise. In some regions of Italy, above all in Brianza north of Milan, San Mamete is venerated by women who have borne a child, in order to obtain an abundant quantity of milk for the newborn. Special rites took place until recent times: the woman who felt the need to ask the help of the Saint went to the church bringing some bread and some cheese, which she placed upon the altar for some time, she went out, was obliged to offer the bread and cheese to the first person she encountered. She hoped; the Battle of São Mamede is considered a crucial event that led to the foundation of the Kingdom of Portugal. A number of places in Portugal are named after this Christian saint, such as São Mamede, a quarter of Lisbon, São Mamede de Este, a town in Braga, São Mamede de Infesta, a town in Matosinhos, the Igreja de São Mamede, a church building in Évora, the Serra de São Mamede, a mountain range in Portalegre District and São Mamede de Coronado, a town in Trofa, as well as São Mamede, Paraíba, a municipality in the state of Paraíba, Brazil
Constantinople was the capital city of the Roman Empire, of the Byzantine Empire, of the brief Crusader state known as the Latin Empire, until falling to the Ottoman Empire. It was reinaugurated in 324 from ancient Byzantium as the new capital of the Roman Empire by Emperor Constantine the Great, after whom it was named, dedicated on 11 May 330; the city was located in what is now the core of modern Istanbul. From the mid-5th century to the early 13th century, Constantinople was the largest and wealthiest city in Europe; the city was famed for its architectural masterpieces, such as the Greek Orthodox cathedral of Hagia Sophia, which served as the seat of the Ecumenical Patriarchate, the sacred Imperial Palace where the Emperors lived, the Galata Tower, the Hippodrome, the Golden Gate of the Land Walls, the opulent aristocratic palaces lining the arcaded avenues and squares. The University of Constantinople was founded in the fifth century and contained numerous artistic and literary treasures before it was sacked in 1204 and 1453, including its vast Imperial Library which contained the remnants of the Library of Alexandria and had over 100,000 volumes of ancient texts.
It was instrumental in the advancement of Christianity during Roman and Byzantine times as the home of the Ecumenical Patriarch of Constantinople and as the guardian of Christendom's holiest relics such as the Crown of Thorns and the True Cross. Constantinople was famed for its complex defences; the first wall of the city was erected by Constantine I, surrounded the city on both land and sea fronts. In the 5th century, the Praetorian Prefect Anthemius under the child emperor Theodosius II undertook the construction of the Theodosian Walls, which consisted of a double wall lying about 2 kilometres to the west of the first wall and a moat with palisades in front; this formidable complex of defences was one of the most sophisticated of Antiquity. The city was built intentionally to rival Rome, it was claimed that several elevations within its walls matched the'seven hills' of Rome; because it was located between the Golden Horn and the Sea of Marmara the land area that needed defensive walls was reduced, this helped it to present an impregnable fortress enclosing magnificent palaces and towers, the result of the prosperity it achieved from being the gateway between two continents and two seas.
Although besieged on numerous occasions by various armies, the defences of Constantinople proved impregnable for nearly nine hundred years. In 1204, the armies of the Fourth Crusade took and devastated the city, its inhabitants lived several decades under Latin misrule. In 1261 the Byzantine Emperor Michael VIII Palaiologos liberated the city, after the restoration under the Palaiologos dynasty, enjoyed a partial recovery. With the advent of the Ottoman Empire in 1299, the Byzantine Empire began to lose territories and the city began to lose population. By the early 15th century, the Byzantine Empire was reduced to just Constantinople and its environs, along with Morea in Greece, making it an enclave inside the Ottoman Empire. According to Pliny the Elder in his Natural History, the first known name of a settlement on the site of Constantinople was Lygos, a settlement of Thracian origin founded between the 13th and 11th centuries BC; the site, according to the founding myth of the city, was abandoned by the time Greek settlers from the city-state of Megara founded Byzantium in around 657 BC, across from the town of Chalcedon on the Asiatic side of the Bosphorus.
The origins of the name of Byzantion, more known by the Latin Byzantium, are not clear, though some suggest it is of Thraco-Illyrian origin. The founding myth of the city has it told that the settlement was named after the leader of the Megarian colonists, Byzas; the Byzantines of Constantinople themselves would maintain that the city was named in honour of two men and Antes, though this was more just a play on the word Byzantion. The city was renamed Augusta Antonina in the early 3rd century AD by the Emperor Septimius Severus, who razed the city to the ground in 196 for supporting a rival contender in the civil war and had it rebuilt in honour of his son Marcus Aurelius Antoninus, popularly known as Caracalla; the name appears to have been forgotten and abandoned, the city reverted to Byzantium/Byzantion after either the assassination of Caracalla in 217 or, at the latest, the fall of the Severan dynasty in 235. Byzantium took on the name of Kōnstantinoupolis after its refoundation under Roman emperor Constantine I, who transferred the capital of the Roman Empire to Byzantium in 330 and designated his new capital as Nova Roma'New Rome'.
During this time, the city was called'Second Rome','Eastern Rome', Roma Constantinopolitana. As the city became the sole remaining capital of the Roman Empire after the fall of the West, its wealth and influence grew, the city came to have a multitude of nicknames; as the largest and wealthiest city in Europe during the 4th–13th centuries and a centre of culture and education of the Mediterranean basin, Constantinople came to be known by prestigious titles such as Basileuousa and Megalopol
Kievan Rus' was a loose federation of East Slavic and Finnic peoples in Europe from the late 9th to the mid-13th century, under the reign of the Varangian Rurik dynasty. The modern nations of Belarus and Ukraine all claim Kievan Rus' as their cultural ancestors, with Belarus and Russia deriving their names from it. At its greatest extent, in the mid-11th century, it stretched from the Baltic Sea in the north to the Black Sea in the south and from the headwaters of the Vistula in the west to the Taman Peninsula in the east, uniting the majority of East Slavic tribes. According to Russian historiography, the first ruler to start uniting East Slavic lands into what has become known as Kievan Rus' was Prince Oleg, he extended his control from Novgorod south along the Dnieper river valley to protect trade from Khazar incursions from the east, he moved his capital to the more strategic Kiev. Sviatoslav I achieved the first major expansion of Kievan Rus' territorial control, fighting a war of conquest against the Khazars.
Vladimir the Great introduced Christianity with his own baptism and, by decree, extended it to all inhabitants of Kiev and beyond. Kievan Rus' reached its greatest extent under Yaroslav the Wise; the state declined beginning in the late 11th century and during the 12th century, disintegrating into various rival regional powers. It was further weakened by economic factors, such as the collapse of Rus' commercial ties to the Byzantine Empire due to the decline of Constantinople and the accompanying diminution of trade routes through its territory; the state fell to the Mongol invasion of the 1240s. During its existence, Kievan Rus' was known as the "land of the Rus'", in Greek as Ῥωσία, in Old French as Russie, Rossie, in Latin as Russia, from the 12th century Ruthenia. Various etymologies have been proposed, including Ruotsi, the Finnish designation for Sweden, Ros, a tribe from the middle Dnieper valley region. In the Norse sources, the sagas, the principality is called Garðariki, the peoples, according to Snorre Sturlason, are called Suiones, the confederation of Great Sviþjoð were made up of the peoples along the Dniepr called Tanais that separated Asia and Europe, all the way to the Baltics and Scandinavia.
The term Kievan Rus' was coined in the 19th century in Russian historiography to refer to the period when the centre was in Kiev. In English, the term was introduced in the early 20th century, when it was found in the 1913 English translation of Vasily Klyuchevsky's A History of Russia, to distinguish the early polity from successor states, which were named Rus; the Russian term was rendered into Belarusian and Ukrainian as Кіеўская Русь and Ки́ївська Русь, respectively. Prior to the emergence of Kievan Rus' in the 9th century AD, the lands between the Baltic Sea and Black Sea were populated by eastern Slavic tribes. In the northern region around Novgorod were the Ilmen Slavs and neighboring Krivichi, who occupied territories surrounding the headwaters of the West Dvina and Volga Rivers. To their north, in the Ladoga and Karelia regions, were the Finnic Chud tribe. In the south, in the area around Kiev, were the Poliane, a group of Slavicized tribes with Iranian origins, the Drevliane to the west of the Dnieper, the Severiane to the east.
To their north and east were the Vyatichi, to their south was forested land settled by Slav farmers, giving way to steppelands populated by nomadic herdsmen. Controversy persists over whether the Rus' were Slavs; this uncertainty is due to a paucity of contemporary sources. Attempts to address this question instead rely on archaeological evidence, the accounts of foreign observers, legends and literature from centuries later. To some extent the controversy is related to the foundation myths of modern states in the region. According to the "Normanist" view, the Rus' were Scandinavians, while Russian and Ukrainian nationalist historians argue that the Rus' were themselves Slavs. Normanist theories focus on the earliest written source for the East Slavs, the Primary Chronicle, although this account was not produced until the 12th century. Nationalist accounts have suggested that the Rus' were present before the arrival of the Varangians, noting that only a handful of Scandinavian words can be found in modern Russian and that Scandinavian names in the early chronicles were soon replaced by Slavic names.
Archaeological evidence from the area suggests that a Scandinavian population was present during the 10th century at the latest. On balance, it seems that the Rus' proper were a small minority of Scandinavians who formed an elite ruling class, while the great majority of their subjects were Slavs. Considering the linguistic arguments mounted by nationalist scholars, if the proto-Rus' were Scandinavians, they must have become nativized, adopting Slavic languages and other cultural practices. Ahmad ibn Fadlan, an Arab traveler during the 10th century, provided one of the earliest written descriptions of the Rus': "They are as tall as a date palm and ruddy, so that they do not need to wear a tunic nor a cloak. Liutprand of C
International Standard Serial Number
An International Standard Serial Number is an eight-digit serial number used to uniquely identify a serial publication, such as a magazine. The ISSN is helpful in distinguishing between serials with the same title. ISSN are used in ordering, interlibrary loans, other practices in connection with serial literature; the ISSN system was first drafted as an International Organization for Standardization international standard in 1971 and published as ISO 3297 in 1975. ISO subcommittee TC 46/SC 9 is responsible for maintaining the standard; when a serial with the same content is published in more than one media type, a different ISSN is assigned to each media type. For example, many serials are published both in electronic media; the ISSN system refers to these types as electronic ISSN, respectively. Conversely, as defined in ISO 3297:2007, every serial in the ISSN system is assigned a linking ISSN the same as the ISSN assigned to the serial in its first published medium, which links together all ISSNs assigned to the serial in every medium.
The format of the ISSN is an eight digit code, divided by a hyphen into two four-digit numbers. As an integer number, it can be represented by the first seven digits; the last code digit, which may be 0-9 or an X, is a check digit. Formally, the general form of the ISSN code can be expressed as follows: NNNN-NNNC where N is in the set, a digit character, C is in; the ISSN of the journal Hearing Research, for example, is 0378-5955, where the final 5 is the check digit, C=5. To calculate the check digit, the following algorithm may be used: Calculate the sum of the first seven digits of the ISSN multiplied by its position in the number, counting from the right—that is, 8, 7, 6, 5, 4, 3, 2, respectively: 0 ⋅ 8 + 3 ⋅ 7 + 7 ⋅ 6 + 8 ⋅ 5 + 5 ⋅ 4 + 9 ⋅ 3 + 5 ⋅ 2 = 0 + 21 + 42 + 40 + 20 + 27 + 10 = 160 The modulus 11 of this sum is calculated. For calculations, an upper case X in the check digit position indicates a check digit of 10. To confirm the check digit, calculate the sum of all eight digits of the ISSN multiplied by its position in the number, counting from the right.
The modulus 11 of the sum must be 0. There is an online ISSN checker. ISSN codes are assigned by a network of ISSN National Centres located at national libraries and coordinated by the ISSN International Centre based in Paris; the International Centre is an intergovernmental organization created in 1974 through an agreement between UNESCO and the French government. The International Centre maintains a database of all ISSNs assigned worldwide, the ISDS Register otherwise known as the ISSN Register. At the end of 2016, the ISSN Register contained records for 1,943,572 items. ISSN and ISBN codes are similar in concept. An ISBN might be assigned for particular issues of a serial, in addition to the ISSN code for the serial as a whole. An ISSN, unlike the ISBN code, is an anonymous identifier associated with a serial title, containing no information as to the publisher or its location. For this reason a new ISSN is assigned to a serial each time it undergoes a major title change. Since the ISSN applies to an entire serial a new identifier, the Serial Item and Contribution Identifier, was built on top of it to allow references to specific volumes, articles, or other identifiable components.
Separate ISSNs are needed for serials in different media. Thus, the print and electronic media versions of a serial need separate ISSNs. A CD-ROM version and a web version of a serial require different ISSNs since two different media are involved. However, the same ISSN can be used for different file formats of the same online serial; this "media-oriented identification" of serials made sense in the 1970s. In the 1990s and onward, with personal computers, better screens, the Web, it makes sense to consider only content, independent of media; this "content-oriented identification" of serials was a repressed demand during a decade, but no ISSN update or initiative occurred. A natural extension for ISSN, the unique-identification of the articles in the serials, was the main demand application. An alternative serials' contents model arrived with the indecs Content Model and its application, the digital object identifier, as ISSN-independent initiative, consolidated in the 2000s. Only in 2007, ISSN-L was defined in the
Alexei Alexandrovich Shakhmatov was a Russian philologist and historian credited with laying foundations for the science of textology. Born in Narva, present-day Estonia, Shakhmatov was brought up by his uncle near Saratov, he went to a public school in Moscow and developed interest for Old Russian language and literature at an early age. At the age of 16, his articles started to appear in the most authoritative journal of Slavic studies of that time, the Archive of Slavic Philology. Shakhmatov furthered his education at the Moscow University delivering lectures in the same institution, his first monograph, published in 1886, examined the language of ancient Novgorod charters. In 1891 he became so enthusiastic about zemstvo that he gave up his scholarly pursuits for three years and held a minor administrative office in his native village. In 1894, Shakhmatov returned to Moscow and won great acclaim for his Ph. D. dissertation, entitled Studies in the Sphere of Russian Phonetics. Five years he was admitted to the Russian Academy of Sciences, over the following years became one of the most reputable academicians.
He revived the Academy's linguistic periodicals, edited the academic dictionary of Russian language and was elected to represent the Academy at the State Council of Imperial Russia and Imperial State Duma. In 1909, Shakhmatov moved to work at Saint Petersburg University as a professor. By that time, he had been elected doctor honoris causa by the Charles University, Berlin University, Polish Academy of Sciences, many other scholarly societies. Shakhmatov participated in the Commission for the Study of the Tribal Composition of the Population of the Borderlands of Russia set up in February 1917, he helped prepare sweeping reforms of Russian orthography, which would be implemented by the Bolsheviks in 1918. Shakhmatov refused to leave Petrograd for the West, a fatal decision that led to his premature death from malnutrition and exhaustion in 1920; the Academy subsequently cherished his memory and instituted a special Shakhmatov Prize, to be awarded "for the best works in source science and linguistics".
Shakhmatov is best remembered for having pioneered textological research of early Russian chronicles, notably the Primary Chronicle. He established with a great degree of precision the stages of evolution of that key document attempting to reconstruct the postulated proto-version of Nestor's chronicle, his research proved seminal for subsequent generations of historians. Shakhmatov was responsible for publication and pioneering studies of minor or derelict Slavic languages, his studies of Slavic etymology revolved around the idea of close contacts and influences between the ancient Slavs and Celts, a hypothesis, subsequently discarded. In particular, Shakhmatov was convinced that Prekmurje Slovene, spoken in Prekmurje and the Slovene March, contains Celtic elements due to its front rounded vowels ü and ö. In fact, Prekmurje Slovene is dialect of Slovene, the sounds ü and ö are common in other dialects of Slovene, such as in Prlekija and some parts of Carinthia. Hungarian nationalists employed this theory of Shakhmatov against the Slovenes as part of magyarization of the Slovene March
Rus'–Byzantine War (907)
The Rus'–Byzantine War of 907 is associated in the Primary Chronicle with the name of Oleg of Novgorod. The chronicle implies that it was the most successful military operation of the Kievan Rus' against the Byzantine Empire. Paradoxically, Greek sources do not mention it at all; the chronicle describes the raid of 907 in considerable detail. The memory of the campaign seems to have been transmitted orally among several generations of the Rus; this may account for the abundance of colorful facts. We are told at first that the Byzantine envoys attempted to poison Oleg before he could approach Constantinople; the Rus' leader, renowned for his oracular powers, refused to drink from the poisoned cup. When his navy was within sight of Constantinople, he found the city gate closed and the entry into the Bosporus barred with iron chains. At this point, Oleg resorted to subterfuge: he effected a landing on the shore and had some 2,000 dugout boats equipped with wheels. After his boats were thus transformed into vehicles, he led them to the walls of Constantinople and fixed his shield to the gates of the Imperial capital.
The threat to Constantinople was relieved by peace negotiations which bore fruit in the Russo-Byzantine Treaty of 907. Pursuant to the treaty, the Byzantines paid a tribute of twelve grivnas for each Rus' boat; that Oleg's campaign is not fiction is clear from the authentic text of the peace treaty, incorporated into the chronicle. Current scholarship tends to explain the silence of Greek sources with regard to Oleg's campaign by the inaccurate chronology of the Primary Chronicle; some assume that the raid took place in 904, when the Byzantines were at war with Leo of Tripoli. A more plausible conjecture has been advanced by Boris Rybakov and Lev Gumilev: the account of the campaign in fact refers to the Rus'-Byzantine War, erroneously described in Slavonic sources as a Kievan failure. Despite recurrent military conflicts, the relations between the Rus' and Byzantium seem to have been predominantly peaceful; the First Christianization of the Rus' was reported by Patriarch Photius in the 860s.
In one of his letters, Patriarch Nicholas Mysticus threatened to unleash a Rus' invasion of Bulgaria. Historians infer from his account that the Byzantines were able to manipulate the Rus' of Oleg's time for their own political ends. Furthermore, substantial contingents of the Rus' joined the imperial service and took part in the Byzantine naval expeditions throughout the 10th century. A squadron of 700 Rus' mercenaries participated in the Crete expedition of 902. A unit of 415 Varangians was involved in the Italian expedition of 936. Thirteen years 629 Rus' troops sailed on nine vessels to accompany the Greeks in their expedition against the Emirate of Crete. Rus'–Byzantine Treaty Andrey Nikolayevich Sakharov. Дипломатия древней Руси: IX – первая половина X в. Moscow, 1980. Analysis of Nestor's account of the expedition on www.textology.ru