Sometimes called Pietro Laurati, Lorenzetti was an influential Italian painter born in Siena and active between 1306 and 1345. He was influenced by Giovanni Pisano (1250 – 1315) and Giotto (1267 – 1337), and also worked alongside the Sienese painter Simone Martini (1284 – 1344) at Assisi. He and his brother, Ambrogio Lorenzetti (1290 – 1348), helped introduce naturalism into the otherwise mystical Sienese art. In their artistry were experiments with three-dimensional and spatial arrangements, which foreshadowed the art of the Renaissance.
Many of Lorenzetti’s religious works are in churches in Siena, Arezzo, and Assisi. One of his last works is the Nativity of the Virgin (1342), now in the Museo dell'Opera del Duomo. His masterwork is a tempera fresco decoration of the lower church of Basilica of San Francesco d'Assisi, where he painted a series of large panels depicting the Crucifixion, Deposition from the Cross, and Entombment with emotional figures. The massed figures in these scenes are governed by geometric emotional interactions, unlike many prior scenographic depictions, which appeared to be the independent iconic agglomerations, as if independent figures had been glued on to a surface, with no compelling relationship to one another.
The narrative influence of Giotto's frescoes in the Bardi and Peruzzi Chapels in Santa Croce in Florence and the Arena Chapel in Padua can be seen in these and other works of the lower church at Assisi. The Lorenzetti brothers and their contemporary competitor from Florence, Giotto, but also his followers Bernardo Daddi (1280 – 1348) and Maso Di Banco (d.1348), seeded the Italian pictorial revolution that extracted figures from the gilded ether of iconic Byzantine art into the pictorial worlds of towns, land, and air. Sienese iconography was generally more mystical and fantastic than the more naturalistic Florentines, and at times, seems to elevate into what appears a modern surrealist landscape.
Of Lorenzetti’s works now in the Uffizi Gallery are the Madonna and Child with Angels, an altarpiece painted around 1340 fro the church of San Francesco in Pistoia, also his Beata Umiltà Altarpiece, painted for the women’s convent of the Donne di Faenza in Florence, probably also in the artist’s later period around 1340.