At which battle did Cyrus the Great defeat the Median king Astyages around 550 BCE?

Cyrus the Great defeated the Median king Astyages at the Battle of Pasargadae around 550 BCE.

The conflict marked the rise of Cyrus and the creation of the Achaemenid Persian Empire. Cyrus, previously a subordinate ruler under Median power according to the traditional account, rebelled against Astyages and defeated him near Pasargadae.

Ancient sources preserve different versions of the campaign. Herodotus presents a dramatic story involving Median nobles who abandoned Astyages, while other accounts emphasize battles and political realignment. The exact battlefield and sequence of events remain debated by historians.

The victory did not simply destroy every Median institution. Cyrus inherited and adapted many Median practices, officials, and traditions. Persian imperial rule grew from this combined Persian and Median political foundation rather than from an entirely new system.