Of him there are hardly any news; between 1270 and 1280, in Rome, he worked on the frescoes, now lost, with stories of the Old and New Testament in S. Paolo's Basilica ; in 1291 , already in full artistic maturity, he worked on the lower mosaics in S. Maria in Trastevere's apse in Rome ; around 1293 he frescoed the inside of S. Cecilia in Trastevere (iter 5) ; in 1308 he was in Naples in Carlo d'Angiò's court attending to the decoration of S. Maria Donna Regina; according to news given by Ghiberti, during the papacy of John XXII (1316-34) he allegedly completed the mosaics, these too were destroyed, on S. Paolo's façade in Rome (iter 2) . Together with Cimabue and Duccio, Cavallini is one of those that renewed Italian painting at the end of the thirteenth century, and Giotto certainly looked to him to draw that research for the fusion of color that in Giotto has such an effectiveness of expression. The oldest of his works known to this time, that is the storie della Madonna in the mosaics in S. Maria in Trastevere (iter 5), reveals in Cavallini ‘s art an enduring Byzantine influence, but in the ensemble of the composition can already be noted an aulic nobility and the tendency to subordinate every other demand to a lively sense of color, that it's so easily enriched with light as it's obfuscated by shadows. S. Cecilia's frescoes are instead works of full maturity, of which unfortunately only a large fragment of the Last Judgment remain, and, by the hand of his collaborators, some remainders of the storie dei due Testamenti . In these frescoes Cavallini 's art is enriched by a new sense of dignity and of classical composure: the bodies of his severe characters, nobly wearing paludaments, are reproduced with a richness of light and shade and with a very original color fusion that models the plastic masses with degrading and delicate shadings; also because of the effort of an in-depth approach to the characters' psychology and the stress on depicting man in its physical and spiritual integrity, Cavallini shows to have risen above all the formulas of the Byzantine tradition and pre-announces the profound humanity of Giotto's art. It's not an easy task to ascertain just how much of S. Maria Donna Regina's fresco work belongs to Cavallini and how much was done instead by his collaborators; also there's a discussion on whether to attribute the Albero di Jesse in Naples' Dome (around 1308) to the maestro, or the Madonna in trono con S. Matteo, S. Francesco e il card. D'Acquasparte (around 1302) in S. Maria d'Aracoeli in Rome (iter 1), while even more in doubt is his participation in the frescoing of the superior church of S. Francesco in Assisi , for instance in the storie di Isacco , by now there's a general inclination to see Giotto's hand in this work.