Tetrarchy
The term "tetrarchy" describes any form of government where power is divided among four individuals, but in modern usage refers to the system instituted by Roman Emperor Diocletian in 293, marking the end of the Crisis of the Third Century and the recovery of the Roman Empire. This tetrarchy lasted until c. 313, when mutually destructive civil wars eliminated most of the claimants to power, leaving Constantine in control of the western half of the empire, Licinius in control of the eastern half. Although the term "tetrarch" was current in antiquity, it was never used of the imperial college under Diocletian. Instead, the term was used to describe independent portions of a kingdom that were ruled under separate leaders; the tetrarchy of Judaea, established after the death of Herod the Great, is the most famous example of the antique tetrarchy. The term was understood in the Latin world as well, where Pliny the Elder glossed it as follows: "each is the equivalent of a kingdom, part of one"; as used by the ancients, the term describes not only different governments, but a different system of government from the Diocletianic arrangements.
The Judaean tetrarchy was a set of four independent and distinct states, where each tetrarch ruled a quarter of a kingdom as they saw fit. When authors described the period, this is what they emphasized: Ammianus had Constantius II admonish Gallus for disobedience by appealing to the example in submission set by Diocletian's lesser colleagues. Only Lactantius, a contemporary of Diocletian and a deep ideological opponent of the Diocletianic state, referred to the tetrarchs as a simple multiplicity of rulers. Much modern scholarship was written without the term. Although Edward Gibbon pioneered the description of the Diocletianic government as a "New Empire", he never used the term "tetrarchy", it did not appear in the literature until used in 1887 by schoolmaster Hermann Schiller in a two-volume handbook on the Roman Empire, to wit: "die diokletianische Tetrarchie". So, the term did not catch on in the literature until Otto Seeck used it in 1897; the first phase, sometimes referred to as the diarchy, involved the designation of the general Maximian as co-emperor—firstly as Caesar in 285, followed by his promotion to Augustus in 286.
Diocletian took care of matters in the eastern regions of the empire while Maximian took charge of the western regions. In 293, Diocletian thought that more focus was needed on both civic and military problems, so with Maximian's consent, he expanded the imperial college by appointing two Caesars —Galerius and Constantius Chlorus. In 305, the senior emperors jointly abdicated and retired, allowing Constantius and Galerius to be elevated in rank to Augustus, they in turn appointed two new Caesars—Severus II in the west under Constantius, Maximinus in the east under Galerius—thereby creating the second Tetrarchy. The four tetrarchs based themselves not at Rome but in other cities closer to the frontiers intended as headquarters for the defence of the empire against bordering rivals and barbarians at the Rhine and Danube; these centres are known as the tetrarchic capitals. Although Rome ceased to be an operational capital, Rome continued to be nominal capital of the entire Roman Empire, not reduced to the status of a province but under its own, unique Prefect of the City.
The four tetrarchic capitals were: Nicomedia in northwestern Asia Minor, a base for defence against invasion from the Balkans and Persia's Sassanids was the capital of Diocletian, the eastern Augustus. Sirmium was the capital of the eastern Caesar. Mediolanum was the capital of the western Augustus. Augusta Treverorum was the capital of Constantius Chlorus, the western Caesar, near the strategic Rhine border; this quarter became the prefecture Galliae. Aquileia, a port on the Adriatic coast, Eboracum, were significant centres for Maximian and Constantius respectively. In terms of regional jurisdiction there was no precise division among the four tetrarchs, this period did not see the Roman state split up into four distinct sub-empires; each emperor had his zone of influence within the Roman Empire, but little more high command in a'war theater'. Each tetrarch was himself in the field, while delegating most of the administration to the hierarchic bureaucracy headed by his respective Pretorian Prefect, each supervising several Vicarii, the governors-general in charge of another, lasting new administrative level, the civi
Simon Corcoran
Simon Corcoran is a British ancient historian and lecturer in ancient history within the School of History and Archaeology, Newcastle University. Corcoran was a senior research fellow at University College, London from 1999 to 2015, he received his D. Phil. From St John's College, Oxford in 1992, he was awarded the Henryk Kupiszewski Prize for his book The Empire of the Tetrarchs in 1998. At University College he worked on'Projet Volterra', an extensive on-line public database of law for the period AD193–900. From 2014 Corcoran has been a member of the Steering Committee of the British Epigraphy Society, he is a Consulting Editor for the Journal of Late Antiquity and a Scientific Advisor for Revue Antiquité tardive. From 2006 to 2009 he served on the Council of the Society for the Promotion of Hellenic Studies and on the council for the British Institute at Ankara from 2011 to 2015. In 2016 Corcoran was a member of the panel for BBC Radio 4's In Our Time episode on Justinian's Legal Code with Caroline Humfress and Paul du Plessis.
In 2010 the Volterra database was used by Corcoran and Salway to identify unknown fragments of the Gregorian Code. The "Fragmenta Londiniensia" are seventeen pieces of parchment estimated to date from AD400, the document having been cut up and re-used as book-binding material; this is the first direct evidence yet discovered of the Gregorian Codex. Greed is a motive everyone. Lactantius includes greed and avarice as a notable part of the tetrarchic maladministration practised by Diocletian, Maximian and Maximinus, indeed the cause of the inflation the edict seeks to curb, thus it is Diocletian's greed. Frier, Bruce W. Cambridge University Press, ISBN 1107119820 Corcoran, The Empire of the Tetrarchs, Imperial Pronouncements and Government AD 284–324, Oxford University Press, ISBN 0-19-815304-X Corcoran, Simon. "The Würzburg fragment of Justinian's constitutions for the administration of recovered Africa". In Freu, C.. Mélanges d'histoire romaine et d'Antiquité tardive offerts à Jean-Michel Carrié.
Brepols. Pp. 96–113. ISBN 9782503566757. Archived from the original on 2016-11-18. Corcoran, Simon. "Roman law in Ravenna". In Herrin, J. Institute of Historical Research. Pp. 163–197. ISBN 9781909646148. Corcoran, Simon. "Sixth Book, First to Twentieth Titles". In Frier, B; the Codex of Justinian. A New Annotated Translation with Parallel Latin and Greek Text. Cambridge University Press. Pp. 1407–1485. ISBN 9780521196826. Corcoran, Simon. "The Augusti and Caesars say: Imperial communication in a collegiate monarchy". Official Epistolography and the Language of Power. Proceedings of the 1st International Conference of the Research Network Imperium and Officium. Vienna: Verlag. Pp. 219–236. ISBN 9783700177050. Corcoran, Simon. "From unholy madness to right-mindedness: or how to legislate for religious conformity from Decius to Justinian". Conversion in Late Antiquity: Christianity and Beyond: Papers from the Andrew W. Mellon Foundation Sawyer Seminar, University of Oxford, 2009-2010. Routledge. Pp. 67–94. ISBN 9781409457381.
Corcoran, Simon. "Hincmar and his Roman legal sources". Hincmar of Rheims. Manchester University Press. Pp. 129–155. Corcoran, Simon. "State correspondence in the Roman Empire: Imperial communication from Augustus to Justinian". In Radner, Karen. State Correspondence in the Ancient World. New York: Oxford University Press. Pp. 172–209. Corcoran, The Gregorianus and Hermogenianus assembled and shattered, Mélanges de l’École française de Rome - Antiquité, ISSN 0223-5102 Corcoran, Simon, "Grappling with the Hydra: co-ordination and conflict in the management of Tetrarchic succession", in Bonamente, Giorgio; the Fragmenta Londiniensia Anteiustiniana, 127, Zeitschrift der Savigny-Stiftung für Rechtsgeschichte. Romanistische Abteilung, v127 n1, ISSN 0323-4096 Corcoran, Simon, "Anastasius and the Pagans: A Tale of Two Law Codes and a Papyrus", Journal of Late Antiquity, 2.2: 183–208, doi:10.1353/jla.0.0049, ISSN 1939-6716 Corcoran, Simon, "After Kruger: Observations on some additional or revised Justinian Code headings and subscripts", Zeitschrift der Savigny-Stiftung für Rechtsgeschichte.
Romanistische Abtheilung, 126: H. Böhlau: 423, ISSN 0323-4096, OCLC 440690826 Corcoran, Simon, "New subscripts for old rescripts: The Vallicelliana fragments of Justinian Code Book VII", Zeitschrift der Savigny-Stiftung für Rechtsgeschichte. Romanistische Abtheilung, 126: H. Böhlau: 401, ISSN 0323-4096, OCLC 440690823 Corcoran, Simon, "Two tales, two cities: Antinoopolis and Nottingham", in Drinkwater, John.
Barter
In trade, barter is a system of exchange where participants in a transaction directly exchange goods or services for other goods or services without using a medium of exchange, such as money. Economists distinguish barter from gift economies in many ways. Barter takes place on a bilateral basis, but may be multilateral. In most developed countries, barter only exists parallel to monetary systems to a limited extent. Market actors use barter as a replacement for money as the method of exchange in times of monetary crisis, such as when currency becomes unstable or unavailable for conducting commerce. Economists since the times of Adam Smith, looking at non-specific pre-modern societies as examples, have used the inefficiency of barter to explain the emergence of money, of "the" economy, hence of the discipline of economics itself. However, ethnographic studies have shown that no present or past society has used barter without any other medium of exchange or measurement, nor have anthropologists found evidence that money emerged from barter, instead finding that gift-giving was the most usual means of exchange of goods and services.
Adam Smith, the father of modern economics, sought to demonstrate that markets pre-existed the state, hence should be free of government regulation. He argued. Markets emerged, in his view, out of the division of labour, by which individuals began to specialize in specific crafts and hence had to depend on others for subsistence goods; these goods were first exchanged by barter. Specialization depended on trade, but was hindered by the "double coincidence of wants" which barter requires, i.e. for the exchange to occur, each participant must want what the other has. To complete this hypothetical history, craftsmen would stockpile one particular good, be it salt or metal, that they thought no one would refuse; this is the origin of money according to Smith. Money, as a universally desired medium of exchange, allows each half of the transaction to be separated. Barter is characterized in Adam Smith's "The Wealth of Nations" by a disparaging vocabulary: "higgling, swapping, dickering." It has been characterized as negative reciprocity, or "selfish profiteering."Anthropologists have argued, in contrast, "that when something resembling barter does occur in stateless societies it is always between strangers."
Barter occurred between strangers, not fellow villagers, hence cannot be used to naturalistically explain the origin of money without the state. Since most people engaged in trade knew each other, exchange was fostered through the extension of credit. Marcel Mauss, author of'The Gift', argued that the first economic contracts were to not act in one's economic self-interest, that before money, exchange was fostered through the processes of reciprocity and redistribution, not barter. Everyday exchange relations in such societies are characterized by generalized reciprocity, or a non-calculative familial "communism" where each takes according to their needs, gives as they have. Since direct barter does not require payment in money, it can be utilized when money is in short supply, when there is little information about the credit worthiness of trade partners, or when there is a lack of trust between those trading. Barter is an option to those who cannot afford to store their small supply of wealth in money in hyperinflation situations where money devalues quickly.
The limitations of barter are explained in terms of its inefficiencies in facilitating exchange in comparison to money. It is said that barter is'inefficient' because: There needs to be a'double coincidence of wants' For barter to occur between two parties, both parties need to have what the other wants. There is no common measure of value In a monetary economy, money plays the role of a measure of value of all goods, so their values can be assessed against each other. Indivisibility of certain goods If a person wants to buy a certain amount of another's goods, but only has for payment one indivisible unit of another good, worth more than what the person wants to obtain, a barter transaction cannot occur. Lack of standards for deferred payments This is related to the absence of a common measure of value, although if the debt is denominated in units of the good that will be used in payment, it is not a problem. Difficulty in storing wealth If a society relies on perishable goods, storing wealth for the future may be impractical.
However, some barter economies rely on durable goods like sheep or cattle for this purpose. Other anthropologists have questioned whether barter is between "total" strangers, a form of barter known as "silent trade". Silent trade called silent barter, dumb barter, or depot trade, is a method by which traders who cannot speak each other's language can trade without talking. However, Benjamin Orlove has shown that while barter occurs through "silent trade", it occurs in commercial markets as well. "Because barter is a difficult way of conducting trade, it will occur only where there are strong institutional constraints on the use of money or where the barter symbolically denotes a special social relationship and is used in well-defined conditions. To sum up, multipurpose money in markets is like lubrication for machines - necessary for the
Constantine the Great
Constantine the Great known as Constantine I, was a Roman Emperor who ruled between 306 and 337 AD. Born in Naissus, in Dacia Ripensis, town now known as Niš, he was the son of Flavius Valerius Constantius, a Roman Army officer, his mother was Empress Helena. His father became Caesar, the deputy emperor in the west, in 293 AD. Constantine was sent east, where he rose through the ranks to become a military tribune under Emperors Diocletian and Galerius. In 305, Constantius was raised to the rank of Augustus, senior western emperor, Constantine was recalled west to campaign under his father in Britannia. Constantine was acclaimed as emperor by the army at Eboracum after his father's death in 306 AD, he emerged victorious in a series of civil wars against Emperors Maxentius and Licinius to become sole ruler of both west and east by 324 AD. As emperor, Constantine enacted administrative, financial and military reforms to strengthen the empire, he restructured the government, separating military authorities.
To combat inflation he introduced the solidus, a new gold coin that became the standard for Byzantine and European currencies for more than a thousand years. The Roman army was reorganised to consist of mobile field units and garrison soldiers capable of countering internal threats and barbarian invasions. Constantine pursued successful campaigns against the tribes on the Roman frontiers—the Franks, the Alamanni, the Goths, the Sarmatians—even resettling territories abandoned by his predecessors during the Crisis of the Third Century. Constantine was the first Roman emperor to convert to Christianity. Although he lived much of his life as a pagan, as a catechumen, he joined the Christian faith on his deathbed, being baptised by Eusebius of Nicomedia, he played an influential role in the proclamation of the Edict of Milan in 313, which declared religious tolerance for Christianity in the Roman empire. He called the First Council of Nicaea in 325, which produced the statement of Christian belief known as the Nicene Creed.
The Church of the Holy Sepulchre was built on his orders at the purported site of Jesus' tomb in Jerusalem and became the holiest place in Christendom. The Papal claim to temporal power in the High Middle Ages was based on the forged Donation of Constantine, he has been referred to as the "First Christian Emperor", he did promote the Christian Church. Some modern scholars, debate his beliefs and his comprehension of the Christian faith itself; the age of Constantine marked a distinct epoch in the history of the Roman Empire. He renamed the city Constantinople after himself, it became the capital of the Empire for more than a thousand years, with the eastern Roman Empire now being referred to as the Byzantine Empire by historians. His more immediate political legacy was that he replaced Diocletian's tetrarchy with the principle of dynastic succession by leaving the empire to his sons, his reputation for centuries after his reign. The medieval church upheld him as a paragon of virtue, while secular rulers invoked him as a prototype, a point of reference, the symbol of imperial legitimacy and identity.
Beginning with the Renaissance, there were more critical appraisals of his reign, due to the rediscovery of anti-Constantinian sources. Trends in modern and recent scholarship have attempted to balance the extremes of previous scholarship. Constantine was a ruler of major importance, he has always been a controversial figure; the fluctuations in his reputation reflect the nature of the ancient sources for his reign. These are abundant and detailed, but they have been influenced by the official propaganda of the period and are one-sided; the nearest replacement is Eusebius's Vita Constantini—a mixture of eulogy and hagiography written between 335 AD and circa 339 AD—that extols Constantine's moral and religious virtues. The Vita creates a contentiously positive image of Constantine, modern historians have challenged its reliability; the fullest secular life of Constantine is the anonymous Origo Constantini, a work of uncertain date, which focuses on military and political events to the neglect of cultural and religious matters.
Lactantius' De Mortibus Persecutorum, a political Christian pamphlet on the reigns of Diocletian and the Tetrarchy, provides valuable but tendentious detail on Constantine's predecessors and early life. The ecclesiastical histories of Socrates and Theodoret describe the ecclesiastic disputes of Constantine's reign. Written during the reign of Theodosius II, a century after Constantine's reign, these ecclesiastic historians obscure the events and theologies of the Constantinian period through misdirection, misrepresentation, deliberate obscurity; the contemporary writings of the orthodox Christian Athanasius and the ecclesiastical history of the Arian Philostorgius survive, though their biases are no less firm. The epitomes of Aurelius Victor, Eutropius and the anonymous author of the Epitome de Caesaribus offer compressed secular political and military histories of the period. Although not Christian, the epitomes paint a favourable image of Constantine but omit reference to Constantine's religious policies.
The Panegyrici Latini, a collection of panegyrics
Lion
The lion is a species in the family Felidae. The lion is sexually dimorphic. Male lions have a prominent mane, the most recognisable feature of the species. A lion pride consists of related females and cubs. Groups of female lions hunt together, preying on large ungulates; the species is an keystone predator, although they scavenge when opportunities occur. Some lions have been known to hunt humans, although the species does not; the lion inhabits grasslands and savannas but is absent in dense forests. It is more diurnal than other big cats, but when persecuted it adapts to being active at night and at twilight. In the Pleistocene, the lion ranged throughout Eurasia and North America but today it has been reduced to fragmented populations in Sub-Saharan Africa and one critically endangered population in western India, it has been listed as Vulnerable on the IUCN Red List since 1996 because populations in African countries have declined by about 43% since the early 1990s. Lion populations are untenable outside designated protected areas.
Although the cause of the decline is not understood, habitat loss and conflicts with humans are the greatest causes for concern. One of the most recognised animal symbols in human culture, the lion has been extensively depicted in sculptures and paintings, on national flags, in contemporary films and literature. Lions have been kept in menageries since the time of the Roman Empire and have been a key species sought for exhibition in zoological gardens across the world since the late 18th century. Cultural depictions of lions were prominent in the Upper Paleolithic period; the lion's name, similar in many Romance languages, is derived from Latin: leo and Ancient Greek: λέων. The word lavi may be related. Felis leo was the scientific name used by Carl Linnaeus in 1758, who described the lion in his work Systema Naturae; the genus name Panthera was coined by German naturalist Lorenz Oken in 1816. Between the mid-18th and mid-20th centuries, 26 lion specimens were described and proposed as subspecies, of which 11 were recognised as valid in 2005.
They were distinguished on the basis of appearance and colour of mane. Because these characteristics show much variation between individuals, most of these forms were not true subspecies because they were based upon museum material with "striking, but abnormal" morphological characteristics. Based on the morphology of 58 lion skulls in three European museums, the subspecies krugeri, nubica and senegalensis were assessed distinct but bleyenberghi overlapped with senegalensis and krugeri; the Asiatic lion persica was the most distinctive and the Cape lion had characteristics allying it more with persica than the other sub-Saharan lions. The lion's closest relatives are the other species of the genus Panthera. Results of phylogenetic studies published in 2006 and 2009 indicate that the jaguar and the lion belong to one sister group that diverged about 2.06 million years ago. Results of studies published in 2010 and 2011 indicate that the leopard and the lion belong to the same sister group, which diverged between 1.95 and 3.10 million years ago.
Hybridisation between lion and snow leopard ancestors, may have continued until about 2.1 million years ago. In the 19th and 20th centuries, several lion type specimens were described and proposed as subspecies, with about a dozen recognised as valid taxa until 2017. Between 2008 and 2016, IUCN Red List assessors used only two subspecific names: P. l. leo for African lion populations and P. l. persica for the Asiatic lion population. In 2017, the Cat Classification Task Force of the Cat Specialist Group revised lion taxonomy, recognises two subspecies based on results of several phylogeographic studies on lion evolution, namely: P. l. leo − the nominate lion subspecies includes the Asiatic lion, the regionally extinct Barbary lion, lion populations in West and northern parts of Central Africa. Synonyms include P. l. persica, P. l. senegalensis, P. l. kamptzi, P. l. azandica. Some authors referred to it as'Northern lion' and'northern subspecies'. P. l. melanochaita − includes the extinct Cape lion and lion populations in East and Southern African regions.
Synonyms include P. l. somaliensis, P. l. massaica, P. l. sabakiensis, P. l. bleyenberghi, P. l. roosevelti, P. l. nyanzae, P. l. hollisteri, P. l. krugeri, P. l. vernayi, P. l. webbiensis. It has been referred to as'southern subspecies'. Early phylogenetic research was focused on East and Southern African lions, showed they can be divided in two main clades. Lions in eastern Kenya are genetically much closer to lions in Southern Africa than to lions in Aberdare National Park in western Kenya. In a subsequent study and bone samples of 32 lion specimens in museums were used. Results indicated lions form
Debasement
Debasement is the practice of lowering the value of currency. It is used in connection with commodity money such as gold or silver coins. A coin is said to be debased if the quantity of gold, copper or nickel is reduced. For example, the value of the denarius in Roman currency decreased over time as the Roman government altered both the size and the silver content of the coin; the silver used was nearly pure, weighing about 4.5 grams. From time to time, this was reduced. During the Julio-Claudian dynasty, the Denarius contained 4 grams of silver, was reduced to 3.8 grams under Nero. The Denarius continued to shrink in size and purity, until by the second half of the third century, it was only about 2% silver, was replaced by the Argenteus; because of huge wealth, the Vijayanagara Empire in modern-day South India issued large quantities of gold coins. Harihara I and Bukka Raya I, who founded the Vijayanagar Empire, minted gold coins using debased gold. Gold fanams and its fractions were minted by them for medium-end transactions.
One reason a government will debase its currency is financial gain for the sovereign at the expense of citizens. By reducing the silver or gold content of a coin, a government can make more coins out of a given amount of specie. Inflation follows, allowing the sovereign to repudiate government bonds. However, the purchasing power of the citizens’ currency has been reduced. Another reason is to end a deflationary spiral. Debasement was the result of the value of the precious metal content rising above the face value of coins; as the market price of precious metal rose, the intrinsic value of coins would rise above the face value and so a profit could be made from using coins as bullion rather than monetary instrument. This gave an incentive to money changers and mint masters to practice illegal debasement via clipping and sweating. Coins would be melted down and exported. To anticipate these illegal debasements and preserve the quality and quantity of coins, the king would either debase or cry up the coinage.
Thus, debasement had its legitimate purposes and was welcome by the population if done to preserve the stability of the coinage. Debasement lowers the intrinsic value of the coinage and so more coins can be made with the same quantity of precious metal. If done too debasement may lead to a new coin being adopted as a standard currency, as when the Ottoman Akçe was replaced by the kuruş, with the para as a subunit; the kuruş in turn became a subdivision of the lira. Methods of coin debasement The mint starts issuing coins of a certain face value, but with less metal content than previous issues. There will be an incentive to bring the old coins to the mint for re-minting – see Gresham's law. A revenue, called seigniorage, is made on this minting process. "Debasement" is sometimes used to refer to the tendency of silver or gold coins to be "shaved", that is, to have small amounts shaved off the edges of the coins by unscrupulous users, thereby reducing the actual precious metal content of the coin.
In order to prevent this and gold coins began to be produced with milled edges, as many coins still do by tradition, although they no longer contain valuable metals. For example, the U. S. quarter and dime have milled edges. Coins that have traditionally been made purely of base metals, such as the U. S. nickel or the penny, are more to have unmilled edges. By analogy, "debased currency" is sometimes used for anything whose value has been reduced, such as "Stardom is an utterly debased currency" Financial repression, similar process via different mechanism Money burning
Tyrian purple
Tyrian purple known as Tyrian red, Phoenician purple, royal purple, imperial purple or imperial dye, is a reddish-purple natural dye. It is a secretion produced by several species of predatory sea snails in the family Muricidae, rock snails known by the name Murex. In ancient times, extracting this dye involved tens of thousands of snails and substantial labor, as a result, the dye was valued; the main chemical is 6,6′-dibromoindigo. Tyrian purple may first have been used by the ancient Phoenicians as early as 1570 BCE; the dye was prized in antiquity because the colour did not fade, but instead became brighter with weathering and sunlight. Its significance is such that the name Phoenicia means'land of purple.' It came in various shades, the most prized being that of "blackish clotted blood". Tyrian purple was expensive: The 4th century BCE historian Theopompus reported, "Purple for dyes fetched its weight in silver at Colophon" in Asia Minor; the expense meant that purple-dyed textiles became status symbols, whose use was restricted by sumptuary laws.
The most senior Roman magistrates wore a toga praetexta, a white toga edged with a stripe of Tyrian purple. The more sumptuous toga picta, solid Tyrian purple with a gold stripe, was worn by generals celebrating a Roman triumph; the toga picta was worn by the Roman emperors, to the point that'purple' is sometimes used as a metonym for the office. The production of Tyrian purple was controlled in the succeeding Byzantine Empire and subsidized by the imperial court, which restricted its use for the colouring of imperial silks. A child born to a reigning emperor was said to be porphyrogenitos, "born in the purple"; some speculate that the dye extracted from the Bolinus brandaris is known as argaman in Biblical Hebrew. Another dye extracted from a related sea snail, Hexaplex trunculus, produced a blue colour after light exposure which could be the one known as tekhelet, used in garments worn for ritual purposes; the dye substance is a mucous secretion from the hypobranchial gland of one of several species of medium-sized predatory sea snails that are found in the eastern Mediterranean Sea.
These are the marine gastropods Bolinus brandaris the spiny dye-murex, the banded dye-murex Hexaplex trunculus, the rock-shell Stramonita haemastoma, less a number of other species such as Bolinus cornutus. The dye is an organic compound of bromine, a class of compounds found in algae and in some other sea life, but much more found in the biology of land animals. In nature the snails use the secretion as part of their predatory behaviour in order to sedate prey and as an antimicrobial lining on egg masses; the snail secretes this substance when it is attacked by predators, or physically antagonized by humans. Therefore, the dye can be collected either by "milking" the snails, more labour-intensive but is a renewable resource, or by collecting and destructively crushing the snails. David Jacoby remarks that "twelve thousand snails of Murex brandaris yield no more than 1.4 g of pure dye, enough to colour only the trim of a single garment."Many other species worldwide within the family Muricidae, for example Plicopurpura pansa, from the tropical eastern Pacific, Plicopurpura patula from the Caribbean zone of the western Atlantic, can produce a similar substance and this ability has sometimes been exploited by local inhabitants in the areas where these snails occur.
The dog whelk Nucella lapillus, from the North Atlantic, can be used to produce red-purple and violet dyes. The Phoenicians made an indigo dye, sometimes referred to as royal blue or hyacinth purple, made from a related species of marine snail; the Phoenicians established an ancillary production facility on the Iles Purpuraires at Mogador, in Morocco. The sea snail harvested at this western Moroccan dye production facility was Hexaplex trunculus known by the older name Murex trunculus; this second species of dye murex is found today on the Mediterranean and Atlantic coasts of Europe and Africa. The colour-fast dye was an item of luxury trade, prized by Romans, who used it to colour ceremonial robes. Used as a dye, the color shifts from blue to reddish-purple, it is believed that the intensity of the purple hue improved rather than faded as the dyed cloth aged. Vitruvius mentions the production of Tyrian purple from shellfish. In his History of Animals, Aristotle described the shellfish from which Tyrian purple was obtained and the process of extracting the tissue that produced the dye.
Pliny the Elder described the production of Tyrian purple in his Natural History: The most favourable season for taking these is after the rising of the Dog-star, or else before spring. After it is taken, the vein is extracted, which we have spoken of, to which it is requisite to add salt, a sextarius about to every hundre
