 A succession of popes and architects followed in the next 120 years, their combined efforts resulting in the present building.The scheme begun by Julius II continued through the reigns of Leo X (1513–1521), Hadrian VI (1522–1523).Clement VII (1523–1534), Paul III (1534–1549), Julius III (1550–1555), Marcellus II (1555), Paul IV (1555–1559), Pius IV (1559–1565), Pius V (saint) (1565–1572), Gregory XIII (1572–1585), Sixtus V (1585–1590), Urban VII (1590), Gregory XIV (1590–1591), Innocent IX (1591), Clement VIII (1592–1605), Leo XI (1605), Paul V (1605–1621), Gregory XV (1621–1623), Urban VIII (1623–1644) and Innocent X (1644–1655).