Therefore, Messer Giorgio, my friend, I pray you that on my part you will thank the Duke for his most gracious offer, and that you will ask his Lordship to give me leave to continue here until such time as I can depart with fame and honour and without sin.
"The eleventh day of May, 1555.
"Your MICHAEL ANGELO BUONARROTI, in Rome." Early in the year 1557 serious illness seized Michael Angelo, and his good friends the Cardinal of Carpi, Donato Giannotti, Tomaso Cavalieri, Francesco Bandini, and Lottino ultimately succeeded in persuading him to make a model of his cupola, that the work might not be impeded or altered in the event of his death.

He mentions this in a letter to his nephew, Lionardo.( 167) "I prayed his Lordship that he would concede me so much time that I could leave the works at St.Peter's at such a point that my plans could not be changed.

As yet this point has not been reached; and more, I am now obliged to construct a large wooden model for the cupola and lantern, to secure its being finished as it was meant to be.

All Rome, and especially the Cardinal of Carpi, prayed me to do this, so that I believe that I shall have to remain here not less than a year; and so much time I beg the Duke to allow me for the love of Christ and Saint Peter, so that I may come home to Florence without such a grief, but with a mind free from the necessity of returning to Rome." This model was constructed by a French master, named Jean, and took a year to make, as Michael Angelo expected.
Continuous intrigues caused Michael Angelo to send in his resignation in a haughty letter dated February 13, 1560, but Pius IV.

confirmed the aged artist in his office, and forbade any alteration of his design for Saint Peter's after his death.