The Vatican Massacre was a mass murder that occurred on the command of Cesare Borgia after his death a few days before in Naples. The massacre is known as the Red Hat Massacre.As per the wishes of Cesare[a], the murder and subsequent pillaging was restricted to the Vatican and other Papal lands in Rome.
In Italy, Angevin armies marched in both the north and south of the Peninsula, surrounding the core territories belonging to the Borgia family. Cesare I's own death in battle in Naples against Arthur I of France served as a rallying cry for his supporters and allies in Italy; yet also served to generate resistance to the Borgia empire from vassals in the east and north.
Cesare's chief gonfaloniere in Rome, Augusto Deramo, led the assault on the Vatican early in the morning on 4 June, roughly 5 days after Cesare's death. With knowledge of Duke xxx of xxx's march north from the south, he acted upon what Cesare called his final act, the name taken from the parchment delivered from Naples to Rome.