Coello was the court painter for King Charles II of Spain. His most famous work is the Sacristy in El Escorial which contains his altarpiece of The Adoration of the Miraculous Host. This monumental work contains fifty portraits, including that of the king and the principal courtiers.

This work of bravura Spanish Baroque painting was probably executed c.1683 when Coello painted frescoes in the Augustinian church at Zaragoza.

Augustine served as Bishop of Hippo Regius in Alexandria and is regarded as one of the most important Church Fathers. He was a prolific writer but he perhaps remains best known for his Confessions, which is a personal account of this earlier life.

Augustine is often shown with the attribute of a flaming heart which seems to indicate the intensity of his love of God.