Villa Mondragone was born as an offshoot of Villa Vecchia in 1567. It is built on the structure of an ancient Roman villa that once belonged to the consuls Quintili. When the building was sold to Cardinal Ugo Boncompagni, who became Pope Gregory XIII, he used it regularly as a residence. Here in 1582 he promulgated the papal bull 'inter gravissimas', which reformed the calendar as that which is now in use, and which takes its name from the pope: the Gregorian Calendar. The name of the villa is derived from the pope's coat of arms that included a dragon. The villa had its heyday with Cardinal Scipione Borghese, who became Pope Paul V, and with his family. In 1626 Pope Urban VIII decided to leave Villa Mondragone in favour of a papal residence in Castel Gandolfo. In 1858 the villa was the setting of the novel 'The Daniella' by George Sand. In 1865, Prince Borghese gave the villa to the Jesuits who turned it into a prestigious college. Here in 1912 W.M. Voynich purchase from the Jesuits the famous Voynich Manuscript. During the Second World War the villa was refuge to the local population and then was closed. Today the building is the conference centre of the University of Rome Tor Vergata.