Paolo Uccello

Paolo Uccello became so consumed by the mathematics of perspective, still a new and difficult technique in 15th-century Florence, that his own biographer made a joke out of it. Giorgio Vasari, writing decades after Uccello's death, recorded that his wife complained he stayed up all night in his study working through perspective problems, and when she called him to bed, he would answer, "what a sweet thing this perspective is."

His friend, the sculptor Donatello, reportedly told him he was abandoning substance for shadow, wasting a painter's gift on geometric exercises better suited to inlaid woodwork. Uccello kept at it anyway. His three large panels of the Battle of San Romano, painted in the 1430s and 1440s for a palace of Florence's ruling Medici family and today split between the Uffizi, the Louvre, and London's National Gallery, are full of foreshortened lances lying on the ground, all pointing toward the same vanishing point, a battlefield turned into a geometry lesson he clearly couldn't resist.

He died in Florence in 1475. In his own tax return six years earlier, he had written: "I find myself old and ailing, my wife is ill, and I can no longer work."