Mithridates VI was the son of Mithridates V (150 BC–120 BC), who died when he was a boy. During Eupator's minority, supreme power was exercised by his mother queen Laodice, whom he eventually deposed and committed to prison (ca. 115 BC). However, his mother - in an attempt to be queen and have the throne of the kingdom of Pontus - killed off many of his brothers but not his sister, Laodice, whom he married.
Mithridates entertained ambitions of making his state the dominant power in the Black Sea and Anatolia. After he subjugated Colchis, the king of Pontus clashed for supremacy in the Pontic steppe with the Scythian king Palacus. The most important centres of Crimea, Tauric Chersonesus and the Bosporan Kingdom, readily surrendered their independence in return for Mithridates' promises to protect them against the Scythians, their ancient enemies. After several abortive attempts to invade the Crimea, the Scythians and the allied Rhoxolanoi suffered heavy losses at the hands of the Pontic general Diophantus and accepted, albeit at the point of the sword, Mithridates as their overlord.
The young king then turned his attention to Anatolia, where the Roman power was on the rise. He contrived to partition Paphlagonia and Galatia with Nicomedes III of Bithynia. It soon became clear to Mithridates that Nicomedes steered his country into an anti-Pontic alliance with the expanding Roman Republic. When Mithridates fell out with Nicomedes over control of Cappadocia and defeated him in a series of battles, the latter was constrained to openly enlist the assistance of Rome. The Romans twice interfered into the conflict on behalf of Nicomedes (92 and 95 BC), making the Roman-Pontic war inevitable.
The kingdom Pontus comprised a mixed population in its Ionian Greek and Anatolian cities. The royal family became fully hellenised after the capital was moved to the Greek city of Sinope. Its rulers tried to fully assimilate the potential of their subjects by showing a Greek face to the Greek world and an Iranian/Anatolian face to the Eastern world. Whenever the gap between the rulers and their Anatolian subject became greater, they would put emphasis on their Persian origins. In this manner, the royal propaganda claimed heritage both from Persian and Greek rulers, including Cyrus, Darius I, Seleucus I and Alexander the Great. Mithridates too posed as the champion of Hellenism, but this was mainly to further his political ambitions; it is no proof that he felt a mission to promote its extension within his domains. Whatever his true intentions, the Greek cities (including Athens) defected to the side of Mithridates and welcomed his armies in mainland Greece, while his fleet besieged the Romans at Rhodes.
After conquering western Anatolia in 88 BC, Mithridates VI reportedly ordered the killing of all Romans living there. The massacre of allegedly 80,000 Roman men, women and children in an incident known as the Asiatic Vespers brought matters to a head. During the First Mithridatic War fought between 88 BC and 84 BC, Lucius Cornelius Sulla forced Mithridates VI out of Greece proper but then had to return to Italy to answer the threat posed by Gaius Marius; subsequently, Mithridates VI was defeated but not beaten. A peace was made between Rome and Pontus, but this proved a mere temporary setback.
Mithridates recouped his forces, and when Rome attempted to annex Bithynia, Mithridates VI attacked with an even larger army, leading to the Second Mithridatic War from 83 BC to 82 BC. First Lucullus and then Pompey the Great were sent against Mithridates VI, who was at last defeated by Pompey in the Third Mithridatic War of 75 BC to 65 BC.
After his final defeat in 65 BC, Mithridates VI fled to Crimea and attempted to raise yet another army to take on the Romans but failed to do so. In 63, he withdrew to the citadel in Panticapaeum. Later he marched north with a small number of men. At Colchis he commandeered a fleet and went to his eldest son, Manchares, the king of Cimmerian Bosporus. However, Manchares, whose kingdom had been reorganized by the Romans, was unwilling to recognize his father. Mithridates had Manchares killed, and Mithridates took the throne of the Bosporan Kingdom. Mithridates then ordered the conscription of many Scythians in order to regain his kingdom. Pharnaces II, his younger son, led a new Scythian rebellion against his father. This rebellion was stirred by Roman exiles that Mithridates kept as the core of his Pontic army. Mithridates eventually committed suicide and was buried in Sinope, the capital of Pontus.
Certainly influenced by Alexander the Great, Mithridates VI extended his propaganda from "defender" of Greece to the "great liberator" of the Greek world as war with Rome became inevitable. The Romans were easily translated into "barbarians," in the same sense as the Persian Empire during the war with Persia in the first half of the 5th century and during Alexander's campaign. How many Greeks genuinely bought into this claim will never be known. It served its purpose, however. At least partially because of it, Mithridates VI was able to fight the First War with Rome on Greek soil, and maintain the allegiance of Greece. His campaign for the allegiance of the Greeks was aided in no small part by his enemy Sulla, who allowed his troops to sack the city of Delphi, letting them blow off steam, and plundered many of the city's most famous treasures to help finance his military expenses.
Dio Cassius' Roman History, on the other hand, records his death as murder:
At the behest of Pompey, Mithridates' body was later buried alongside his ancestors at Sinope. (Book 37, chapter 14). Although he died at Panticapaeum, it is the town of Eupatoria in Crimea that commemorates his name.
Various legends are told of Mithridates VI of Pontus. First, he was supposed to have had a prodigious memory: Pliny the Elder and other historians report that Mithridates could speak the languages of all the twenty-two nations he governed. ("Mithridates, who was king of twenty-two nations, administered their laws in as many languages, and could harangue each of them, without employing an interpreter.") Pliny's account is referred to in the story Funes the Memorious by Jorge Luis Borges. After his polyglottism, some books with samples of many different languages have been published under the title of Mithridates.
Furthermore, Mithridates is said to have lived for seven years in the wilderness as a child, following the assassination of his father, Mithridates V, in 120 BCE. Here he grew strong and accustomed to hardship, before taking on the throne and initiating his conquest of the Black Sea and Asia.
Mithridates is most famously said to have sought to harden himself against poison, both by taking increasing sub-lethal doses of the poisons to build tolerance, and by fashioning a 'universal antidote' to protect him from all earthly poisons. Aulus Cornelius Celsus describes this complex antidote, named Antidotum Mithridaticum, in his De Medicina:
Another large antidote, comprising 54 ingredients, was described by Pliny the Elder in Natural History. The antidote was put in a closed flask in which it was to stay for at least two months. Every day Mithridates VI took this medicine to counteract possible attempts to poison him.
Mithridate was a complicated mixture of ingredients used to cure poisoning during the Renaissance Period. Antidotum Mithridaticum, or Theriac, was used for about 1900 years after Mithridates' death. The most famous sort is called Theriacum Andromachi after Nero's physician.
The king's anti-poison routines were supervised by the Agari, a group of Scythian shamans who never left him. Mithridates was guarded in his sleep by a horse, a bull, and a stag, which would whinny, bellow, and bleat whenever anyone approached the royal bed.
The demise of Mithridates VI is detailed in the 1673 play Mithridates written by Jean Racine. This play is the basis for several 18th century operas including one of Mozart's earliest, known most commonly by its Italian name, Mitridate, re di Ponto (1770). The Last King is a historical novel by Michael Curtis Ford about the King and his exploits against the Roman Republic.
In The Grass Crown (novel) the second in the Masters of Rome series, Colleen McCullough, the Australian writer, describes in detail the various aspects of his life - the murder of his sister/wife Laodice, his experiments with poison, and his fear and hatred of Rome. The aging Gaius Marius meets Mithridates in the palace of Ariarathes in Eusebeia Mazaca, a city in Cappadocia, and the former Roman Consul, quite alone and surrounded by the Pontic army, orders Mithridates to leave Cappadocia immediately and go back to Pontus - which he does.
Mithridates the Great is a major character in Poul Anderson's novel The Golden Slave.