Hellanikos, Thukydides and the Era of Kimon

The first historian to record the period from the Persian Wars to 431 BC was Hellanikos, the author of a now lost History of Athens from its mythical origins through the fifth century BC. According to Hellanikos, there was one war between Athens and Sparta from 431 to 421 and another from 412 to 404, and the first of these two wars was the outcome of events which took place in the 430s.

Thukydides, writing a monograph on a war he sought to establish as the most disastrous to date, criticised Hellanikos as chronologically inaccurate and lacking an appreciation of the impact of a stronger Athens. Thukydides asserted that there was only one war, beginning in 431 and ending in 404. Its cause was the growth of Athens following the Persian Wars, and the fear that growth inspired in Sparta.

In the dispute between Thukydides and Hellanikos, scholars have long taken it for granted that the preserved historian was right and the lost historian was mistaken, despite the fact that certain events - the battle of Oinoe, for example - do not fit into the chronology of Thukydides. By restoring the dates recorded by Hellanikos, however, a reliable chronology of the period can be established.