Giovanni Sforza

Giovanni Sforza d'Aragona (5 July 1466 – 27 July 1510) was an Italian  who ruled as Lord of and  from 1483 to his death.

In 1492, Pope Alexander VI arranged a marriage between his thirteen-year-old daughter Lucrezia Borgia and Giovanni in order to improve relations between the Papacy and Milan. Alexander eventually turned against Milan, leaving the marriage useless to the Pope. Lucrezia's brother Cesare threatened to have Giovanni murdered, forcing him to flee. In 1497, the Pope had the marriage annulled by having Giovanni declared impotent, much to the latter's humiliation.

Reference

 * Assassin's Creed: Brotherhood