Who was the last Achaemenid king?

Darius III was the last Achaemenid king of Persia. He ruled from 336 to 330 BCE, when Alexander the Great’s Macedonian invasion brought the Achaemenid Empire to an end.

Darius was not a direct son of the previous king but a relatively distant member of the Achaemenid royal family. He came to the throne after the murder of Artaxerxes III and the brief reign of Artaxerxes IV Arses. His reign was dominated by the rapidly advancing Macedonian army.

Darius suffered major defeats at Issus in 333 BCE and Gaugamela in 331 BCE. He fled eastward after Gaugamela, hoping to organize resistance, but was killed in 330 BCE by the satrap Bessus. Alexander then claimed the Persian kingship. Artaxerxes III was an important predecessor, while Cyrus the Great founded the empire and Xerxes I ruled much earlier.