SassettaSassetta, the subtle genius from Siena, revolutionized Italian painting with an altarpiece for the small Tuscan town of Borgo San Sepolcro in 14371444. Originally standing some six yards high, double sided, with a splendid gilt frame over the main altar of the local Franciscan church, it was the Rolls Royce of early Renaissance painting. But its myriad figures and scenes tempted the collectors of the nineteenth and twentieth centuries, and today its