Sano di Pietro was among the most successful artists in fifteenth-century Siena. Unusually for artists of the time, we have an abundance of documentary facts about his life and artistic activity. His year of birth is usually listed as 1406, but according to a now-lost register of baptisms, he was christened on December 2, 1405.

Sano spent almost his entire career in Siena, and in 1428 was registered there as a painter in the Guild. He was employed continuously by the Comune of Siena from 1445, when he signed a fresco of the Coronation of the Virgin in the Palazzo Pubblico. He also produced predellas, altarpieces and bicherna covers for the Comune.

Sano was equally well patronized by the e...