Cleopatra was queen of Egypt (51–30 BC). In 48 BC, with the aid of Julius Caesar, she overthrew her husband, brother, co-ruler Ptolemy XIII. She became Caesar's mistress, but returned to Egypt after his assassination in 44 BC. In 41 BC she won Mark Antony's love and they were married in 37 BC. Octavian Caesar (later Augustus) determined to destroy them and in 31 BC their fleet was defeated at the Battle of Actium. They fled and Anthony killed himself; Cleopatra surrendered and, after she failed to win Octavian's affections, killed herself with an asp.