A painter, draughtsman and printmaker, Vanni was the most important and prolific Sienese artist of his generation, and one of the foremost religious painters of the Italian Counter-Reformation. He trained initially in Siena with his stepfather, Arcangelo Salimbeni, and from the early 1580s with the mannerist Giovanni de’ Vecchi in Rome, where he worked on several occasions. Around 1586-87 he was associated with the Carracci in Bologna, and through them became infatuated with the art of Federico Barocci from Urbino, whose stylistic influence dominated Vanni’s work for the rest of his career. His output was almost exclusively religious: he painted altarpieces for almost every major church in Siena, and many more elsewhere in Tuscany. In Rome he executed important commissions for the reformist cardinals Paolo Emilio Sfondrato and Cesare Baronio, and his huge altarpiece on slate of The Fall of Simon Magus painted for St Peter’s in 1603 earned him a knighthood from Pope Clement VIII. Vanni made only three etchings himself, but was very active as a designer of prints for professional engravers, which disseminated his name and inventions throughout Europe.