Della Rovere then won the support of Cesare Borgia and was unanimously elected pope.
This fresco-cycle, with its numerous allusions to contemporary history, is still preserved, and forms the noblest monument of the Rovere pope.
In 1483-5486 Giuliano della Rovere (nephew of Pope Sixtus IV., and afterwards himself Pope Julius II.) caused the castle to be erected by Baccio Pontelli, a little to the east of the ancient city.
As early as the 1st of November Cardinal Giuliano della Rovere was elected by the conclave as Julius II.
Facing the cathedral is the Della Rovere palace erected by Cardinal Giulio della Rovere (Julius II.) from the plans of Giuliano da Sangallo as a kind of university, and now occupied by the prefecture, the post-office and law-courts.
An omophorion of the 11th or 12th century, with scenes from the Gospel in needlework, and a chalice of the 15th century with enamels, given by Cardinal Bessarion, the predecessor of Giuliano della Rovere as commendatory of the abbey, are among its treasures.
Guidubaldo was the last duke of the Montefeltro line; at his death in 1508 he bequeathed his coronet to Francesco Maria della Rovere, nephew of Julius II., and for about a century Urbino was ruled by its second dynasty of the Della Rovere family.