Pazzi conspiracy
In 1478, the Pazzi conspiracy, involving members of the Florentine Pazzi family, and sanctioned by Pope Sixtus IV (a member of the della Rovere family) resulted in an attack on Easter Sunday, which left Lorenzo de' Medici wounded and his brother, the popular Giuliano, dead. Violent reprisals broke out in Florence with members and associates of the Pazzi family killed, including the Archbishop of Pisa, Francesco Salviati, a relative of Pope Sixtus, who was condemned to death and hanged. The Pope responded by arresting the Florentine ambassador, excommunicating Lorenzo de' Medici and the Signoria (Town Council) and forbidding the Florentine clergy from practising.