Pietro Perugino, The Giving of the Keys to St. Peter

1481-82
Fresco
Sistine Chapel, The Vatican

The painting illustrates Matthew 16:19, "I will give to thee the keys of the kingdom of heaven." Peter has his usual short, square beard and balding pate. The twelve apostles have archaizing tunics and mantles, bare heads, and halos. The others standing behind them are arrayed as contemporaries of the artist.

Read more about images of St. Peter.
Also see the Traditio Legis.

Source: this page at Wikimedia Commons.