This letter, sent by Alberti to Ludovico Gonzaga on 27 February 1460, testifies to the start of a relationship that had in fact been inspired by the architect's participation in the 1459 Diet of Mantua convened by Pope Pius II. Alberti writes that he is ready to carry out the Marquis's bidding. He also writes that, because of his poor health, he has decided to spend some time in Cavriana, where Ludovico had a palace that has since disappeared. Finally, in the most important detail from the letter, he announces that he has completed the designs for San Sebastiano, San Lorenzo and the loggia for a monument to Virgil: "They are done, I believe that they will not disappoint you".