There is evidence of mercenaries (misthophoroi (plural), misthios (singular male), misthia (singular female) in Greek) being hired in Ancient Greece from the 6th century BC. The tyrants of that time hired bodyguards from other city-states. It is not known if earlier Aegean armies and navies, such as the Minoans and Mycenaeans, used mercenaries.
Mercenary troops from Caria and Ionia are known to have fought with Psamtik I against the Assyrians. These were the "bronze men from the sea" whose arrival in Egypt, according to Herodotus, was foretold to Psamtik by an oracle. They entered the country as raiders but Psamtik made a truce with them and hired them to his cause. Afterwards, he granted land to them alongside the Nile and they are traditionally held to have been the first Greeks to settle in Egypt.