Antiochus III "Magnus" (c. 243-187 B.C.E.; Seleucid Emperor 223-187 B.C.E.). The son of the Seleucid (Syrian) Emperor Seleucus II and the younger brother of Seleucus III, he inherited the Empire at a very troubled time after his brother died in an accident. He was largely successful in rebuilding the Empire -- until he went to war with Rome. Defeated and forced to make an expensive peace, he was assassinated after trying to rob a temple, and the Seleucid Empire went into a permanent decline thereafter as his descendants fought over the throne.