The success of the Germanicus led to an even more prestigious commission in 1628 for an altarpiece depicting the "Martyrdom of St. Erasmus", for the Erasmus Chapel in the basilica of St. Peter’s (now in the Vatican Pinacoteca). The Fabricca di San Pietro had originally awarded the commission to Pietro da Cortona, who had produced only preliminary designs for the altarpiece when he was unexpectedly transferred to another project. Thanks to Cassiano dal Pozzo’s influence, Poussin was chosen to paint the Saint Erasmus altarpiece, following Pietro da Cortona’s original design.