While Michelangelo had taken Bramante's design for the church and rested on his authority, he had in the course of construction introduced many important modifications into the plan, and stamped the whole monument with the imprint of his own grandiose and heavy genius.
He kept the Greek cross with equal arms and four apses, at the same time hiding the apse of the façade in a rectangular mass against which he wished to[{119}] put a portico with four gigantic columns. He suppressed the salient angles and the towers which should have risen at the extremities of the four arms of the cross. The beautiful clean-cut lines of the curved ends of these arms, which in Bramante's plan stretched out in the form of a semicircular tribune, were smothered in a massive, vigorous envelope which gave the construction the effect of a fortified bastion.
The most beautiful part of the work was the famous dome, where the influence of Brunelleschi combined with the conception of Bramante. Michelangelo said once while he was working on S. Lorenzo in Florence that "it was possible to do differently from Brunelleschi, but not to do better."
He did not fail to remember the masterly dome of S. Maria de Fiore, for as soon as he was appointed to St. Peter's he had the exact measures of this dome from the lantern to the ground, and also the height sent to him. The dimensions that he chose for St. Peter's seem to have been inspired by them.[94]
Bramante in his design as shown by Burckhardt and de Geymueller[95] gave the principal importance to a circular colonnade crowned by statues on which[{120}] the dome seemed to rest. Michelangelo concentrated his attention on the dome itself, subordinating, as ever, grace and harmony to majesty and force. He accentuated the buttresses of the drum with pairs of columns and raised the outer dome of the cupola, whose beautiful curve possesses an impetuous quality which recalls, with less passion and more freedom, the huge octagonal dome of Brunelleschi, crouching on its base like a beast ready to spring.[96] The lofty serenity of the dome of St. Peter's is almost unique in the work of Michelangelo. He had lived so long with the thoughts of Raphael and Bramante that at last their smile was reflected in his work.[97]
Besides this great masterpiece other architectural works filled the end of his life—the rebuilding of the Capitol, the Porta Pia, S. Maria degli Angeli and S. Giovanni dei Fiorentini.
It was in 1548 that Michelangelo presided over[{121}] the erection of the statue of Marcus Aurelius in the square before the Capitol, but his first sketch for the palaces were no earlier than 1546, and when he died the buildings were far from finished.
He never saw the stairway or the colonnades. An engraving of Pérac's executed in 1559 after Michelangelo's own drawings, "ex ipso exemplari Michaelis Bonaroti," and reproduced in the Speculum Romanie Magnificentiæ of Lafreri, show exactly what his plan was and take from him all blame for the incoherencies and vulgarities put into the execution after his death. The beautiful double staircase of the Senatorial Palace and the fountain with the river gods is all his own; but he had meant to put a colonnade crowned by pilasters at the top of the stairway, the windows of the upper story should have been higher and the campanile crenellated.[98] The Porta Pia was at the end of a long[{122}] street which ran from the Monte Cavallo.[99] Michelangelo made three designs for it in 1561, of which Pius IV chose the most reasonable, according to Vasari. This was more to the credit of the pope than the artist, for the plan which was carried out shows, with a few remnants of massive and imperious power, a complete lack of good taste.
He also worked in 1560-1561 at the transformation of the great hall in the baths of Diocletian into the church of S. Maria degli Angeli, but it is almost impossible to judge this now, for his work was entirely changed and disfigured in 1746 by Vanvitelli.
He was no more fortunate with the Church of S. Giovanni dei Fiorentini at Rome, which was another of his great projects, undertaken with enthusiasm and ending in nothing. S. Giovanni had been begun under Leo X by Jacopo Sansovino. Antonio da San Gallo had worked on it later and had made a model of the church, and then the construction had been abandoned. In 1550, at the suggestion of Bindo Altoviti, Michelangelo determined to consecrate himself to this work and had almost persuaded Julius III, but the money was[{123}] lacking.[100] In 1559 the Florentines took up the idea again and decided to put a church of a new plan on the old foundations, and their procurators, Francesco Bandini, Uberto Ubaldini and Tommaso de' Bardi, asked Michelangelo to take charge of it in spite of his duties at St. Peter's. Cosmo de' Medici himself wrote a most flattering letter begging him to accept, and Michelangelo answered the duke that he "considered his wish an order" and had already shown the Florentine deputies several drawings, of which they had chosen the one which he considered the best.[101] "I am sorry," he added, "to be now so old and so little alive that I can not do all I would or all that is my duty to your lordship and the people. Nevertheless I will make the effort by directing everything from my house to accomplish what your lordship desires."[102]