In 1517, the newly completed Palazzo was seized by the first Medici Pope, Leo X, who had not forgotten the complacency of Pope Sixtus IV at the time of the murderous Pazzi conspiracy intended to replace the Medici in Florence, Italy with a Della Rovere regime. From 1753 the vice chancellor was the Jacobite pretender to the thrones of England, Scotland, France, and Ireland, Henry Stuart, Cardinal Duke of York, the Jacobite Henry IX of England and Ireland, and I of Scotland. During the late 17th century former Queen Kristina of Sweden resided here.