At a time when Rome had been deprived for many centuries, not only of good letters and of the glory of arms, but also of all the sciences and fine arts, there was born in that city, by God's will, one Pietro Cavallini, at the very time when Giotto, who may be said to have restored life to painting, had attained to the chief place among the painters of Italy. Pietro, who had been a pupil of Giotto, and had done some mosaics with him in St Peter's, was the first after him who illuminated that art, and who first showed signs that he was not an unworthy pupil of so great a master, when he painted over the door of the sacristy at Araceli, some scenes which are now destroyed by time, and in S. Maria di Trastevere very many coloured things in fresco for the whole church. Afterwards he worked in mosaic in the principal chapel, and did the front of the church, proving that he was capable of working in mosaic without Giotto's assistance, as he had already succeeded in doing in painting. In the church of S. Grisogono he also did many scenes in fresco and endeavoured to make himself known as the best pupil of Giotto and as a good artist. In the Trastevere also he painted almost the whole of the church of S. Cecilia in fresco, and many things in the church of S. Francesco appresso Ripa. He then executed in mosaic the front of S. Paolo, outside Rome, and in the middle nave did many scenes from the Old Testament. In executing some things in fresco for the chapter-house of the first cloister, he displayed such diligence that he was considered by men of judgment to be a most excellent master, and was for the same reason so much favoured by the prelates, that they employed him to do the wall space between the windows inside St Peter's. Among these things he did the four Evangelists, of extraordinary size as compared with the figures of the time usually seen, executed very finely in fresco; also a St Peter and a St Paul, and in the nave a good number of figures, in which, because the Byzantine style greatly pleased him, he always used it in conjunction with that of Giotto. We see by this work that he spared no effort to give his figures the utmost possible relief. But the best work produced by him in that city was in the church of Araceli sul Campidoglio mentioned above, where he painted in fresco on the vaulting of the principal apse, Our Lady with the child in her arms, surrounded by a circle of suns; beneath her is the Emperor Octavian, adorning the Christ who is pointed out to him by the Tiburtine sybil. The figures in this work, as has been said elsewhere, are much better preserved than the others, because dust cannot attack the vaulting so seriously as the walls. After these things Pietro came to Tuscany in order to see the works of the other pupils of his master Giotto, and those of the master himself. Upon this occasion he painted in S. Marco at Florence many figures which are not visible