手持歌利亚头颅的大卫

This is not a painting on canvas or panel. It is a shield, made of leather over wood, curved and meant to be carried in civic parades through Florence rather than taken into a fight. Decorating one with a full Bible scene, instead of a family coat of arms, was very unusual, and hardly any survive by a master's hand. Castagno made it in the 1450s and did something clever with the story. David swings his sling, still in the act of attacking, yet the giant Goliath's severed head already lies at his feet, the stone lodged in its forehead. Both moments happen at once. For Florence, often a smaller power facing bigger enemies, the boy who beats a giant was a favourite image of the city itself.