Probably the older brother of Ambrogio Lorenzetti. His first documented work is an altarpiece painted in 1320 (Arezzo). Unlike his brother and Simone Martini, Pietro Lorenzetti was active almost exclusively in Siena, except for frescoes carried out in Assisi in the Lower Church. He probably died, like his brother, in the Black Death.
active possibly 1306; died probably 1348