The Battle of the Nile in early 47 BC saw the combined Roman–Egyptian armies of Julius Caesar and Cleopatra VII defeat those of the rival Queen Arsinoe IV and King Ptolemy XIII and secure the throne of Egypt.

Caesar had requested reinforcements from his allies who gathered an army of about 13,000 troops trained in the Roman style of warfare under Mithridates of Pergamum, who marched overland from Asia Minor to assist him.

Arriving in Egypt in January, Mithridates stormed and took the strategic city of Pelusium and marched on towards the Nile Delta where he defeated an Egyptian force sent to stop him.

[3] Egypt was now in the hands of Caesar, who then lifted the Second Siege of Alexandria and placed Cleopatra on the throne as co-ruler with another of her brothers, the twelve-year old Ptolemy XIV.

Caesar then uncharacteristically lingered in Egypt until April, enjoying a liaison of about two months with the youthful queen before departing to resume his civil war.