Caesar then became involved with an Egyptian civil war between the child pharaoh and his sister, wife, and co-regent queen, Cleopatra. Perhaps as a result of the pharaoh's role in Pompey's murder, Caesar sided with Cleopatra. He withstood the Siege of Alexandria and later he defeated the pharaoh's forces at the Battle of the Nile in 47 BC and installed Cleopatra as ruler. Caesar and Cleopatra celebrated their victory with a triumphal procession on the Nile in the spring of 47 BC. The royal barge was accompanied by 400 additional ships, and Caesar was introduced to the luxurious lifestyle of the Egyptian pharaohs.