Pope Alessandro XVIII (Latin: Alexander XVIII) is a male Terran and the 399th Pope (Bishop of Rome) of the Catholic Church. He is the son of the late Pope Gregorio XXX and a woman of one of the oldest aristocratic families in Rome. After his father's death in 3055 AD, Alessandro defeated his uncle, Alfonso d'Este, Archbishop of Cologne, with the support of his half-siblings, Cardinals Francesco di Medici and Caterina Sforza. However, it was not Alessandro's choice to succeed his father.