The Romans had invaded the Carthaginian homeland (in what is now north eastern Tunisia) in 256 BC. After initial successes they had left a force of 15,500 men to hold their lodgement over the winter. This force, under Marcus Atilius Regulus, was decisively beaten at the Battle of Tunis in the spring of 255 BC and Regulus captured. 2,000 survivors were besieged in the port of Aspis. The Roman fleet of 390 warships was sent to rescue and evacuate them. A Carthaginian fleet of 200 ships intercepted them off Cape Hermaeum (the modern Cape Bon or ), north of Aspis. The Carthaginians were defeated with 114 of their ships captured, together with their crews, and 16 sunk. What losses the Romans suffered, if any, is not known; most modern historians assume there were none.