Michelangelo took fire at once, and again hastened to Carrara to arrange for marble to be sent to his studio in the Via Mozzi, now the Via S. Zenobi; while the building stone was brought from Fiesole.  Leo X lived only to know that the great man had begun, the new patron being Giulio de’ Medici, natural son of the murdered Giuliano, now a cardinal, and soon, in 1523, to become Pope Clement VII.  This Pope showed deep interest in the project, but wished not only to add tombs of himself and Pope Leo X, but also to build a library for the Laurentian collection, which Michelangelo must design.  A little later he had decided that he would prefer to lie in the choir of the church, and Leo X with him, and instead therefore of tombs Michelangelo might merely make a colossal statue of him to stand in the piazza before the church.  The sculptor’s temper had not been improved by his many years’ experience of papal caprice, and he replied to this suggestion with a letter unique even in the annals of infuriated artists.  Let the statue be made, of course, he said, but let it be useful as well as ornamental:  the lower portion to be also a barber’s shop, and the head, since it would be empty, a greengrocer’s.  The Pope allowed himself to be rebuked, and abandoned the statue, writing a mild and even pathetic reply.

Until 1527 Michelangelo worked away at the building and the tombs, always secretly, behind impenetrable barriers; and then came the troubles which led to the siege of Florence, following upon the banishment of Alessandro, Duke of Urbino, natural son of the very Lorenzo whom the sculptor was to dignify for all time.  By the Emperor Charles V and Pope Clement VII the city was attacked, and Michelangelo was called away from Clement’s sacristy to fortify Florence against Clement’s soldiers.  Part of his ramparts at S. Miniato still remain, and he strengthened all the gates; but, feeling himself slighted and hating the whole affair, he suddenly disappeared.  One story is that he hid in the church tower of S. Niccolo, below what is now the Piazzale dedicated to his memory.  Wherever he was, he was proclaimed an outlaw, and then, on Florence finding that she could not do without him, was pardoned, and so returned, the city meanwhile having surrendered and the Medici again being restored to power.

The Pope showed either fine magnanimity or compounded with facts in the interest of the sacristy; for he encouraged Michelangelo to proceed, and the pacific work was taken up once more after the martial interregnum, and in a desultory way he was busy at it, always secretly and moodily, until 1533, when he tired completely and never touched it again.  A year later Clement VII died, having seen only drawings of the tombs, if those.