Duccio di Buoninsegna (or simply Duccio) was an artist active during the Middle Ages and a defining innovator of the Sienese School. He painted with a linear and decorative style, frequently using gold and strong colors to create linear patterns—the result of combined influences from Byzantine tradition and the French Gothic. Like many artists of his time, Duccio was considered an artisan and a craftsman; his commissions included designing stained-glass windows, painting ceiling coffers, and parade shields, in addition to frescoes and altarpieces in egg-based tempera. Not all of his works have been identified, since Duccio did not always sign them; he produced his work with the help of many students and assistants, including Simone Martini. The majority of his commissions, and his best known works, were of religious subjects.