Ancient Greece: The Kings.

Despite their defeat by the Athenians at the Battle of Marathon in 490 BC, the Persians were not finished with their determination to conquer mainland Greece. For the Persians, Marathon barely registered; the Persians after all controlled almost the entire world: Asia Minor, Lydia, Judah, Mesopotamia, and Egypt.
The loss at Marathon was no more than an irritation to the Persians. Darius was unable to respond immediately to his defeat because of rebellions on the other end of his empire. While he was quelling these, he was killed in battle.
King Xerxes, son of Darius, ascended to the throne…