The Abbey of Cluny in Burgundy was the center of a major monastic movement in the Middle Ages. Its church was the largest Christian building in the world until St. Peter's Basilica was rebuilt in Rome in the 16th century. Today, one transept of the 12th-century abbey church remains, along with 15th-century abbots' residences and 18th-century convent buildings. The so-called "Palace of Pope Gelasius" was built in 1300-1330 in a Gothic style; only the top level clerestory is original. (Gelasius II died at Cluny in 1119 so he never resided in this building.) The bottom two stories were completely renovated in 1873 by Charles-Jean Laisné (a pupil of Viollet-le-Duc).