Context: Julius Caesar has been murdered and his heir Octavian (later to become Augustus) is fighting for control of the Caesarian party against Marc Anthony after they together defeated Brutus and Cassius at the Battle of Philippi in 42 BC.
The battle: Anthony has been blockaded on land and by sea by Octavian's forces. Basically Anthony and Cleopatra's navy is holed up in the Gulf of Ambracia while his army is encamped nearby. Anthony finds himself short on supplies or courage or both and decides to try to make a break for it back to Egypt. Since Octavian has superior numbers this suits him fine and they allow Anthony to reach open water but not to clear the Island of Lefkada and encircle his fleet before it can so so. Battle is joined and Cleopatra flees early on which in turn causes Anthony to flee with some 70 to 80 ships and allowing the rest of their forces to be captured. Ignominy and suicide for both are to come the following year!