The history of the Vatican as a papal residence dates from the 5th cent., when, after Emperor Constantine I had built the basilica of St. Peter's, Pope Symmachus built a palace nearby. The pope usually resided in the Lateran Palace until the "Babylonian captivity" (14th cent.) in Avignon, France. After the return of the papacy to Rome (1377) the Vatican became the usual residence. The Renaissance popes, principally Sixtus IV, Innocent VIII, Alexander VI, Julius II, Leo X, and Clement VII, were great patrons of the arts, and it was they who began to assemble the great collections and to construct the wonderful galleries. Gregory XIII and Sixtus V spent huge sums on the Vatican and also began the Quirinal, a palace that served as the papal residence from the 17th to the 19th cent., was the Italian royal palace from 1870 to 1946, and is now the home of the president of Italy.