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.
But the ministry never had any real hold over the country or parliament, and the dissatisfaction caused by the modus vivendi with Spain, which would have wrought much injury to the Italian wine-growers, led to demonstrations and riots, and a hostile vote in the Chamber produced a cabinet crisis (December 17, 1905); Signor Fortis, however, reconstructed the ministry, inducing the marquis di San Giuliano to accept the portfolio of foreign affairs.
The death of Giuliano in March 1516, however, caused the pope to transfer his ambitions to Lorenzo.
Cesare, who could still count on the Spanish cardinals, wished to prevent the election of Giuliano della Rovere, the enemy of his house, but the latter's chances were so greatly improved that it was necessary to come to terms with him.
Supported by the power of the papacy, with the goodwill of Florence to back him, Giuliano would have found himself in a position somewhat better than that of Cesare Borgia; and Borgia's creation of the duchy of Romagna might have served as his model.
His feud with Lorenzo de' Medici culminated in the Pazzi conspiracy, the tragic sequel to which was the assassination of Giuliano de' Medici (April 26, 1478).
A Spanish army under Raymundo de Cardona and accompanied by Cardinal Giovanni de' Medici and his brother Giuliano entered the republic's territory and demanded ioo,000 florins, the dismissal of Soderini, and the readmission of the Medici.
In the same piazza is the Collegiata (the former cathedral) of the 12th century, enlarged after 1466 by Giuliano da Maiano, whose brother Benedetto erected the chapel of S.
Leonardo's special friend at the papal court was the pope's youngest brother, Giuliano de' Medici, a youth who combined dissipated habits with thoughtful culture and a genuine interest in arts and sciences.
At his death in 1519 Cardinal Giulio de' Medici (son of the Giuliano murdered in the Pazzi conspiracy) took charge of the government; he met with some opposition and had to play off the Ottimati against the Piagnoni, but he did not rule badly and maintained at all events the outward forms of freedom.