Saints Peter and Paul came to Rome to win converts to Christianity soon after Christ’s death, while Simon Magus, claiming to be the son of God, attempted to prove his divinity by flying. Due to Saint Peter’s prayers, the demons supporting Simon abandoned him and he plummeted to his death. This work is probably a studio copy after a lost oil sketch for a huge altarpiece commissioned in 1746 for Saint Peter’s Basilica at the Vatican. Because of the humidity in Saint Peter’s, which quickly ruined paintings, the work was to have been translated into a massive mosaic. However, for reasons that remain unclear, Batoni’s mosaic was never created.