Bearing a sword in his right hand, and a shield in his left, Saint Michael, dressed in red robes, attacks a dragon, the symbol of sin. The upper part of the composition shows three heavenly choirs while, behind the Saint, good angels fight against the rebels, some of whom are represented as having already turned into horrible monsters, symbols of evil. The anonymous painter appears reflected in Saint Michael´s shield, making this the first known self-portrait in Spanish painting. It was made by a painter who knew the Flemish models, but it lacks the hardness and precision of Castilian artists. Its maker´s relation to Andalusian artists can be seen in a certain taste for the sumptuous and decorative, revealed by the profusion of angels and devils, which is also linked to the characteristics of the final stage of gothic art. The painting was acquired from the Hospital of San Miguel in Zafra and has sometimes been attributed to Juan Sánchez de Castro or his followers, though there are no grounds to support this.