Thucydides the son of Olorus was born probably about 460 BC and died about the year 400 BC. When the Peloponnesian War broke out in 431 B.C Thucydides probably took part in some of its early actions. Some time between 430 and 427 he fell ill in the plague, but recovered. In 424 he was appointed general, but his small squadron of ships arrived too late to save the important Athenian colony of Amphipolis from the Spartan commander Brasidas, though he successfully held the nearby port of Eion against Brasidas's attacks. In consequence he was exiled, not returning until twenty years had passed, only to die a few years later.
For much of the period he describes The Peloponnesian War is the only source that survives. The verity of his reports and the justice of his perceptions have been the cause of controversy amongst scholars for centuries. But it is certain that he used his historical imagination to reconstruct only as a last resort. When the various parts of the history were composed, which of these he revised, and whether their chronological inconsistencies are due to later editing — these questions are still unsolved.