BYZANTIUM, a Greek city on the shores of the Bosporus, occupying the most easterly of the seven hills of modern Constan tinople. It was founded by Megarians and Argives under Byzas about 657 B.c., but destroyed in the reign of Darius Hystaspes by the satrap Otanes; it was recolonized by the Spartan Pausanias (479 B.c.) . Its situation was remarkable for beauty and security. It controlled the Euxine grain trade ; the depth of its harbour rendered its quays accessible to vessels of large burden; while the fisheries were so lucrative that the curved inlet, near which it stood became known as the Golden Horn. The population was partly Lacedaemonian and partly Athenian; it was thus a subject of dispute between these States, and was alternately in the posses sion of each, till it fell into the hands of the Macedonians. About seven years after its second colonization, the Athenian Cimon wrested it from the Lacedaemonians ; but in 440 B.C. it returned to its former allegiance. Alcibiades, after a severe blockade (408 B.c.), gained possession of the city through the treachery of the Athenian party ; in 405 B.c. it was retaken by Lysander and placed under a Spartan harmost. It was under the Lacedaemon ians when the Ten Thousand, exasperated by the conduct of the governor, made themselves masters of the city, and would have pillaged it but for the eloquence of Xenophon. In 390 B.C. Thrasybulus expelled the Lacedaemonian oligarchy, and restored democracy and the Athenian influence. • Byzantium joined with Rhodes, Chios, Cos, and Mausolus, king of Caria, in throwing off the yoke of Athens, but sought Athenian assistance when Philip of Macedon advanced against it. The Athenians under Chares suffered a severe defeat from Amyntas, the Macedonian admiral, but in the following year gained a decisive victory under Phocion and compelled Philip to raise the siege. The deliverance of the besieged from a surprise, by means of a flash of light which revealed the advancing Macedonian army, has rendered this siege memorable. As a memorial of the miracu lous interference, the Byzantines erected an altar to Torch-bearing Hecate, and stamped a crescent on their coins, a device which is retained by the Turks to this day.
During the reign of Alexander, Byzantium was compelled to acknowledge the Macedonian supremacy; after the decay of the Macedonian power it regained its independence, but suffered from the incursions of the Scythians. The losses which they sustained by land roused the Byzantines to indemnify themselves from the vessels which crowded the harbour, and the merchantmen which cleared the straits ; but this had the effect of provoking a war with the neighbouring naval Powers. The exchequer being drained to buy off the Gauls about 279 B.C., and by the imposition of an annual tribute of 8o talents, they were compelled to exact a toll on all the ships which passed the Bosporus—a measure which the Rhodians avenged by a war wherein the Byzantines were defeated.
During the first years of its alliance with Rome, Byzantium held the rank of a free confederate city; but, having sought arbitration on some of its domestic disputes, it was subjected to the imperial jurisdiction, and gradually stripped of its privileges. The Emperor Claudius remitted the heavy tribute which had been imposed on it ; but the last remnant of its independence was taken away by Vespasian, who taunted the inhabitants with having "forgotten to be free." The city was besieged and taken (A.D. 196) by Severus, who destroyed it, demolished the famous wall, and put the principal inhabitants to the sword. This over throw of Byzantium was a great loss to the empire, since it might have served as a protection against the Goths, who afterwards sailed past it into the Mediterranean. Severus afterwards relented, and, rebuilding a large portion of the town, gave it the name of Augusta Antonina. It had scarcely begun to recover its former position when, through the capricious resentment of Gallienus, the inhabitants were once more put to the sword and the town was pillaged. From this disaster the inhabitants recovered so far as to be able to give an effectual check to an invasion of the Goths in the reign of Claudius II., and the fortifications were strengthened during the civil wars which followed the abdication of Diocletian. Diocletian had resolved to transfer his capital to Nicomedia ; but Constantine, struck with the advantages which the situation of Byzantium presented, resolved to build a new city there on the site of the old and transfer the seat of government to it (A.D.
33o). (See CONSTANTINOPLE.)