https://en.wikipedia.org/wiki/Trecento
Period Art. Commonly, the Trecento is considered to be the beginning of the Renaissance in art history. Painters of the Trecento included Giotto di Bondone, as well as painters of the Sienese School, which became the most important in Italy during the century, including Duccio di Buoninsegna, Simone Martini, Lippo Memmi, Ambrogio Lorenzetti and his brother Pietro.