Pazzi conspiracy
In 1481, Pope Sixtus IV summoned Botticelli and other prominent Florentine and Umbrian artists to fresco the walls of the newly completed Sistine Chapel. This large project was to be the main decoration of the chapel. Most of the frescos remain but are greatly overshadowed and disrupted by Michelangelo's work of the next century, as some of the earlier frescos were destroyed to make room for his paintings. The Florentine contribution is thought to be part of a peace deal between Lorenzo Medici and the papacy. After Sixtus was implicated in the Pazzi conspiracy hostilities had escalated into excommunication for Lorenzo and other Florentine officials and a small "Pazzi War".