He achieved a high level of technical refinement and was aware of artistic innovations of talented painters in Florence such as Gentile da Fabriano and Masolino.

Not only does he excel at infusing his figures with a natural light that convincingly molds their shape, he also has an amazing handle on spatial relationships, creating cohesive and impressive work.

Many consider Sassetta's fusing of traditional and contemporary elements as integral to the move from the Gothic to the Renaissance style of painting in Siena.

The unbeliever has been struck dead instantly, and the creature above his face is a tiny black devil which has swooped down to snatch away his soul to the depths of Hell.

[6] It is generally accepted by the art historical community that Sassetta's San Francesco altarpiece was one of the largest and most expensive of the Quattrocento.

[7] The fact that it was produced by a Sienese artist in Siena, and shipped to the Tiber Valley town in late spring 1444 also speaks to Sassetta's fame in his time period.

It has been questioned whether the Scenes from the life of St. Anthony of Egypt are rightly attributed to Sassetta, and critics such as Donald Bruce believe that artists of near-equal talent, such as the Griselda master, also deserve attention for their achievements in art at this period.