The Sistine Chapel was built by will of Pope Sixtus IV between 1475 and 1481, based on a project by Baccio Pontelli. On October 27, 1481, the painters Cosimo Rosselli, Sandro Botticelli, Domenico Ghirlandaio and Pietro Perugino signed a contract for the painting of 10 frescoes in the Chapel. They were requested to paint episodes from the Old and New Testaments, which now cover the building’s long walls and the wall on the opposite facade. The altar wall probably contained two frescoes by Perugino, which Michelangelo destroyed when he began to paint the Last Judgement.