The popes built medieval Rome, the popes financed the Renaissance, and a pope sheltered behind the walls of Castel Sant'Angelo while his city was sacked: three monuments, three chapters of Christian Rome.
Last updated August 23, 2026
In a nutshell: San Giovanni in Laterano served as the popes' grand showcase church through the Middle Ages even as the city around it decayed; St Peter's stands for the Renaissance that papal money set in motion; and Castel Sant'Angelo is bound up with the catastrophe of 1527, when mutinous troops sacked Rome and Clement VII took refuge in the fortress. The history overview sets the scene; the previous chapter is Ancient Rome, and the story continues in Renaissance & Baroque.
For most of the medieval centuries, the Lateran was the popes' grand showcase basilica. All around it, though, the city was collapsing: livestock grazed among the ruins of the forums, and a tattered population kept its head down while Rome's great baronial clans fought one another without pause.
Behind much of the bloodshed lay the long-running clash pitting the Papal States against the Holy Roman Empire. In the end the popes gave up and moved to Avignon, staying there from 1309 to 1377, and then came a schism: two rival popes, with a pope in Rome and another in Avignon, held office at the same time between 1378 and 1417.
St Peter's dominates the skyline, and it remains the greatest emblem of the city's Renaissance. That all-encompassing movement reached Rome from Florence around the middle of the 15th century, bringing an artistic and architectural frenzy in its wake and triggering a wave of building paid for by the popes.
The popes threw themselves into the work: Paul II overhauled Palazzo Venezia, and Sixtus IV, his successor, commissioned the Sistine Chapel. A few decades on, Julius II straightened the line of Via del Corso, putting Bramante in charge of rebuilding St Peter's. Most famously, he hired Raphael to fresco his private rooms at the Vatican Palace, while Michelangelo was set to repainting the Sistine Chapel ceiling.
6 May 1527 was the day Spanish soldiers and German mercenaries, fighting for the emperor Charles V of Spain, invaded the city. What followed was a rampage of brutality that left the local population terrified and forced Clement VII to barricade himself and his entourage inside Castel Sant'Angelo.
Long years of jockeying among Italy's city-states led up to this catastrophe, and its effects were devastating: the papacy staggered, thousands were left dead or homeless, and historians generally judge the sack to have sealed the Roman Renaissance's fate.