In Michelangelo’s Last Judgment, Saint Peter is shown holding the keys to Heaven.
The keys identify Peter as the apostle traditionally regarded as the first pope and the keeper of the keys to the Kingdom of Heaven. Michelangelo placed him among the saints surrounding Christ in the enormous altar-wall fresco, completed for Pope Paul III.
The image is part of a crowded composition showing Christ judging humanity at the end of time. Saints display instruments of their martyrdom or other identifying attributes. Peter’s keys are especially important because they connect the biblical scene with the authority of the papacy, whose ceremonies take place in the chapel.
The keys should not be confused with the flayed skin held by Saint Bartholomew, another frequently discussed detail in the fresco. The skin is traditionally interpreted as containing Michelangelo’s self-portrait, whereas Peter’s keys are a conventional symbol of his apostolic role.