During the time of the Dorian Invasion of Peloponnesus (c. 1068 BC), the Dorians had consulted the Delphic Oracle, which prophesied that their invasion would succeed as long as the king was not harmed. The news of this prophecy, that only the death of an Athenian king would ensure the safety of Athens quickly found their way to the ears of Codrus.
In devotion to his people, Codrus disguised himself as a peasant and made it to the vicinity of the Dorian encampment across the river, where he provoked a group of Dorian soldiers. He was put to death in the quarrel, and the Dorians, realizing Codrus had been slain, decided to retreat in fear of their prophesied defeat.
In the aftermath of these events, no one thought himself worthy to succeed Codrus, the title of king was abolished, and that of archon substituted for it.