Hecataeus of Miletus (; ; c. 550 BC – c. 476 BC), son of Hagesandrus, was an early Greek historian of a wealthy family. He flourished during the time of the Persian invasion. After having travelled extensively, he settled in his native city, where he occupied a high position, and devoted his time to the composition of geographical and historical works. When Aristagoras held a council of the leading Ionians at Miletus to organize a revolt against the Persian rule, Hecataeus in vain tried to dissuade his countrymen from the undertaking. In 494 BC, when the defeated Ionians were obliged to sue for terms, he was one of the ambassadors to the Persian satrap Artaphernes, whom he persuaded to restore the constitution of the Ionic cities. Hecataeus is the first known Greek historian, and was one of the first classical writers to mention the Celtic people.