[2] The greatest and oldest of the offices were the King, the War-lord and the Archon. Of these the office of King was the oldest, for it was ancestral. The second established was the office of War-lord, which was added because some of the Kings proved cowardly in warfare (which was the reason why the Athenians had summoned Ion to their aid in an emergency).1
1 Aristot. Ath. Pol. Fr. 1 above.