He was born and died in Florence, and was the son of the painter Taddeo Gaddi, who was himself the major pupil of the Florentine master Giotto.

Agnolo was a painter and mosaicist, trained by his father, and a merchant as well; in middle age he settled down to commercial life in Venice, and he added greatly to the family wealth.

[1] Agnolo was an influential and prolific artist who was the last major Florentine painter stylistically descended from Giotto.

In Santa Croce, Florence he painted, in eight frescoes, the legend of the Cross, beginning with the archangel Michael giving Seth a branch from the Tree of Knowledge, and ending with the emperor Heraclius carrying the Cross as he enters Jerusalem; in this picture is a portrait of the painter himself.

[2][3] Giorgio Vasari included a biography of Agnolo Gaddi in his Lives of the Most Excellent Painters, Sculptors, and Architects.