Originally a Greek colony, Syracuse was founded in 734 BC on the islet Ortygia, which separates the main harbor from the sea. As it grew the city spread inland over the promontory lying northward of Ortygia and the harbor.
Syracuse assumed a pre-eminent position in the affairs of Sicily under the rule of the tyrants Gelon (485-478 BC) and Hieron (478-467 BC). It grew after the establishment of popular government in 466 BC. According to Thucydides (vi, vii) the Syracusans successfully withstood a famous siege by the Athenians in 414 BC.
Dionysius took advantage of the fear inspired by the Carthaginians to elevate himself to despotic power in 405 BC, and after a reign of 38 years was followed by his son of the same name. Although democratic government was restored by Timoleon after a period of civil dissensions in 344 BC (Plutarch, Timoleon), popular rule did not last.
The most famous of the later rulers was the wise Hieron (275-216 BC), who was the steady ally of the Romans. His grandson and successor Hieronymus deserted the alliance of Rome for that of Carthage, which led to the siege of the city by the Romans under Marcellus and its fall in 212; among the most famous deaths during that period was Archimedes. From that point on Syracuse was the capital of the Roman province of Sicily.