Sassetta (Stefano di Giovanni), perhaps the greatest of the early 15th century Sienese painters. He mingles an innate conservatism, especially in his architectural structures, with a delight in the svelte forms of International Gothic figure design, and in the clarity and unity of Renaissance pictorial space. The essentially 14th century basis of his style, the dreamlike blending of reality and unreality, of graceful calm and visionary fervour, are all epitomized in his dismembered masterpiece, the double-sided altarpiece of 1337-44 for S. Francesco, Borgo S. Sepolcro (part in the Louvre, Paris and National Gallery, London). //