Battle of Actium

In 32 B.C., Mark Antony and Cleopatra traveled to Athens, where she persuaded Antony to officially divorce his wife Octavia. This event was an important spark that led to Rome declaring war on Cleopatra (though not on Mark Antony). Mark Antony however naturally allied with Cleopatra during this war. In 31 B.C. the naval forces of Octavian met those of Antony and Cleopatra at the Battle of Actium.