Darius I - Creator of the Imperial System

S1, E5: Witness the first challenge to the new empire: Was Darius, the son-in-law of Cyrus, a legitimate king? After Cambyses died, and in the face of civil war, Darius established himself as a swift, decisive, unwavering leader. See how Darius created both a royal genealogy and a Persian identity, after which he turned to building infrastructure.