Depends on the pope, I guess Formosus was fired in 896:

The Cadaver Synod (also called the Cadaver Trial; Latin: Synodus Horrenda) is the name commonly given to the ecclesiastical trial of Pope Formosus, who had been dead for about seven months, in the Basilica of St. John Lateran The trial was conducted by Pope Stephen VI, the successor to Formosus’ successor, Pope Boniface VI. Stephen had Formosus’ corpse exhumed and brought to the papal court for judgment. He accused Formosus of perjury, of having acceded to the papacy illegally, and illegally presiding over more than one diocese at the same time.

en.m.wikipedia.org/wiki/Cadaver_Synod