La battaglia tra cristiani e mori a El Sotillo

The event in this picture was already old news when Zurbaran painted it around 1637. It shows a night in 1370, when a Catholic camp was about to be ambushed by Muslim soldiers, and the Virgin Mary is said to have suddenly lit up the sky and given the attack away. Spain had been reconquered from Muslim rule for well over a century by Zurbaran's day, yet stories like this stayed useful, a way of keeping old victories alive. The painting was the centerpiece of an enormous altarpiece, some 30 feet tall, made for a monastery near where the fight supposedly happened. Down below, the two sides clash in darkness. Up above, the sudden light does the real work.