an ancient city of Thrace, situated on the Bosphorus. It was founded, according to Eutropius, about the 30th Olympiad, while Tullus Hostilius reigned in Rome. But, according to Diodorus Siculus, the foundations of this metropolis were laid in the time of the Argonauts, by one Bylas, who then reigned in the neighbouring country, and from whom the city was called Byzantium. This Bylas, according to Eutropius, arrived in Thrace a little before the Argonauts came into those seas, and settled there with a colony of Megarenses. Velleius Paterculus ascribes the founding of Byzantium to the Milesians, and Ammianus Marcellinus to the inhabitants of Attica. Some ancient medals of Byzantium, which have reached our times, bear the name and head of Bylas, with the prow of a ship on the reverse. The year after the destruction of Jerusalem by Titus, Byzantium was reduced to the form of a Roman province. In the year 193 this city took part with Niger against Severus. It was strongly garrisoned by Niger, as being a place of the utmost importance. It was soon after invested by Severus; and as he was universally hated on account of his cruelty, the inhabitants defended themselves with the greatest resolution. They had been supplied with a great number of warlike machines, most of them invented and built by Pericus, a native of Nicaea, and the greatest engineer of his age. For a long time they baffled all the attempts of the assailants, killed great numbers of them, crushed such as approached the walls with large stones; and when stones began to fail, they used the statues of their gods and heroes. At last they were obliged to submit, through famine, after having been reduced to the necessity of devouring one another. The conqueror put all the magistrates and soldiers to the sword; but spared the engineer Pericus. Before this siege, Byzantium was the greatest, most populous, and wealthiest city of Thrace. It was surrounded by walls of an extraordinary height and breadth; and defended by a great number of towers, seven of which were built with such art, that the least noise heard in one of them was immediately conveyed to all the rest. Severus, however, no sooner became master of it, than he commanded it to be laid in ashes. The inhabitants were stripped of all their effects, publicly sold for slaves, and the walls levelled with the ground. But by the chronicle of Alexandria we are informed, that soon after this terrible catastrophe, Severus himself caused a great part of the city to be rebuilt, calling it Antonia from his son Caracalla, who assumed the surname of Byzantium, Antonius. In 262, the tyrant Galienus wreaked his fury on the inhabitants of Byzantium. He intended to besiege it; but on his arrival despaired of being able to make himself master of such a strong place. He was admitted the next day, however, into the city; and without any regard to the terms he had agreed to, caused the soldiers and all the inhabitants to be put to the sword. Trebellius Pollio says, that not a single person was left alive. What the reason was for such an extraordinary massacre, we are nowhere informed. In the wars between the emperors Licinius and Maximin the city of Byzantium was obliged to submit to the latter, but was soon after recovered by Licinius. In the year 323, it was taken from Licinius by Constantine the Great, who in 330 enlarged and beautified it, with a design to make it the second, if not the first, city in the Roman empire. He began with extending the walls of the ancient city from sea to sea; and while some of the workmen were busy in rearing them, others were employed in raising within them a great number of stately buildings, and among others a palace no way inferior in magnificence and extent to that of Rome. He built a capitol and amphitheatre, made a circus maximus, several forums, porticoes, and public baths. He divided the whole city into 14 regions, and granted the inhabitants many privileges and immunities. By this means Byzantium became one of the most flourishing and populous cities of the empire. Vast numbers of people flocked thither from Pontus, Thrace, and Asia, Constantine having, by a law, enacted this year (330), decreed, that such as had lands in those countries should not be at liberty to dispose of them, nor even leave them to their proper heirs at their death, unless they had a house in this new city. But however desirous the emperor was that his city should be filled with people, he did not care that it should be inhabited by any but Christians. He therefore caused all the idols to be pulled down, and all their churches consecrated to the true God. He built besides an incredible number of churches, and caused crosses to be erected in all the squares and public places. Most of the buildings being finished, it was solemnly dedicated to the Virgin Mary, according to Cedrenus, but, according to Eutropius, to the God of Martyrs. At the same time Byzantium was equalled to Rome. The same rights, immunities, and privileges were granted to its inhabitants, as to those of the metropolis. He established a senate and other magistrates, with a power and authority equal to those of old Rome. He took up his residence in the new city; and changed its name to Constantinople.