Cesare Borgia (c.1475/6-1507) was the younger son of Cardinal Roderigo Borgia (later Pope Alexander VI), and after a brief church career became a successful military commander.
Cesare was born in 1475/6, the younger son of Cardinal Roderigo Borgia. Roderigo had risen rapidly in the church with the help of his uncle, Alonso Borgia, bishop of Valencia, and from 1455-58 Pope Calixtus III. During his uncle's papacy Roderigo had been made a cardinal in 1456 when in his mid 20s, appointed vice-chancellor of the Church in 1457 and made archbishop of Valencia in 1458, so Cesare was born into a powerful and very wealthy family.
The original plan had been for Cesare to enter the church, while his elder brother Juan, duke of Gandia, founded a Borgia dynasty. His father became Pope Alexander VI in 1492, and in the same year Cesare was appointed archbishop of Valencia. In 1493 he was made a cardinal, at an even younger age than his father (although he was never ordained as a priest).
Alexander's plans suffered a blow on 14 June 1497 when Juan was murdered. Cesare abandoned his church career, and became captain-general of the Papal armies. In May 1499 he married Charlotte d'Albret and was made Duke of the Valentinois, benefiting from Louis XII's preparations for his invasion of Italy (Second Italian War/ Italian War of Louis XII).
His main task in his new role was to try and restore effective papal control of the Papal States, and at the same time create a base for a Borgia dynasty in the Romagna. He also conquered the duchies of Umbria and Emilia. His conquests were greatly aided by the French, who contributed troops for his conquests of Imola and Forli and his battles in Rimini, Pesaro and Faenza. He also accompanied the French during their 1501 invasion of the kingdom of Naples.
He gained a reputation for ruthlessness, demonstrated when he murdered his sister Lucrezia's second husband, an illegitimate son of the King of Naples who had become a political embarrassment.
In 1503 Alexander died. Cesare had hoped to create a hereditary principality in central Italy, but his illness meant that he was unable to compete with his father's rival Giuliano della Rovere. Alexander was succeeded by the short-lived Paul II, and then later in 1503 by della Rovere, who became Julius II. Cesare was removed from all of his posts, lost control of his fortresses, and was forced into exile in Naples. He was later arrested and sent to Spain, but escaped to Navarre, where he was killed in a fight.
Cesare became the model for Machiavelli's Prince, portrayed as a man of brilliant ruthlessness but dubious achievements. He was also a patron of the arts, employing Leonardo de Vinci as an architect, engineer and city planner. His conquests ended up benefiting the Papacy instead of the Borgia family.