He wrote to his nephew Lionardo on the 13th of February 1557 about the impossibility of meeting the Grand Duke’s wishes and leaving Rome.  “I told his Lordship that I was obliged to attend to S. Peter’s until I could leave the work there at such a point that my plans would not be subsequently altered.  This point has not been reached; and in addition, I am now obliged to construct a large wooden model for the cupola and lantern, in order that I may secure its being finished as it was meant to be.  The whole of Rome, and especially the Cardinal of Carpi, puts great pressure on me to do this.  Accordingly, I reckon 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 S. Peter, so that I may not come home to Florence with a pricking conscience, but a mind easy about Rome.”  The model took about a year to make.  It was executed by a French master named Jean.

All this while Michelangelo’s enemies, headed by Nanni di Baccio Bigio, continued to calumniate and backbite.  In the end they poisoned the mind of his old friend the Cardinal of Carpi.  We gather this from a haughty letter written on the 13th of February 1560:  “Messer Francesco Bandini informed me yesterday that your most illustrious and reverend lordship told him that the building of S. Peter’s could not possibly go on worse than it is doing.  This has grieved me deeply, partly because you have not been informed of the truth, and also because I, as my duty is, desire more than all men living that it should proceed well.  Unless I am much deceived, I think I can assure you that it could not possibly go on better than it now is doing.  It may, however, happen that my own interests and old age expose me to self-deception, and consequently expose the fabric of S. Peter’s to harm or injury against my will.  I therefore intend to ask permission on the first occasion from his Holiness to resign my office.  Or rather, to save time, I wish to request your most illustrious and reverend lordship by these present to relieve me of the annoyance to which I have been subject seventeen years, at the orders of the Popes, working without remuneration.  It is easy enough to see what has been accomplished by my industry during this period.  I conclude by repeating my request that you will accept my resignation.  You could not confer on me a more distinguished favour.”

Giovanni Angelo Medici, of an obscure Milanese family, had succeeded to Paul IV. in 1559.  Pius IV. felt a true admiration for Michelangelo.  He confirmed the aged artist in his office by a brief which granted him the fullest authority in life, and strictly forbade any departure from his designs for S. Peter’s after death.  Notwithstanding this powerful support, Nanni di Baccio Bigio kept trying to eject him from his post.  He wrote to the Grand Duke in 1562, arguing that Buonarroti was in his dotage, and begging Cosimo to use his influence to obtain the place for