Original: In 1502 Leonardo entered the service of Cesare Borgia, the son of Pope Alexander VI, acting as a military architect and engineer and travelling throughout Italy with his patron.
Simplified: The Battle of Anghiari In 1502 and 1503, Leonardo worked for a powerful noble called Cesare Borgia, who was the son of Pope Alexander VI. He travelled around Italy with Borgia, as a military architect and engineer.