Amyntas was the son of the Persian official Bubares by his Macedonian wife Gygaea. He was named after his maternal grandfather, Amyntas I, who ruled Macedonia as a Persian subject from 512/511 BC. Later, King Xerxes I (r. 486-465 BC) gave Amyntas the Carian city of Alabanda. Amyntas was possibly the direct successor of the tyrant Aridolis.