Portrait of Luca Martini

The sheet of paper unrolled across the front of this portrait is a map of the country around Pisa, and it is the reason the picture exists. Luca Martini was Duke Cosimo I's administrator of ditches, galleys and fortresses in Pisa, which in practice meant draining the marshes between Florence and the sea, straightening rivers and keeping the canals open. He held the post from 1547 until his death in 1561. Bronzino painted him in the mid-1550s, deep into that work, and he made the map accurate enough that scholars treat it as one of the earliest measured surveys to appear inside a painting. Martini was not only an engineer. He was a Dante scholar, a patron who found work for sculptors in Pisa, and a friend the painter visited often. The portrait hangs in the Hall of Mars in the Palatine Gallery, a room named for a planet like the rest of that floor.