The son of Faustino Coello, a famous Portuguese sculptor, he was a court painter for Charles II.
His acquaintance with the court painter, Juan Carreño de Miranda, allowed him the permission to visit the royal collection, where he made his greatest advance by studying the works of Titian, Rubens, and van Dyck.
But his principal work is the famous altarpiece in the sacristy of San Lorenzo in the Escorial, representing the Adoration of the Miraculous Host.
In the crowd of personages that form the procession, there are no less than fifty portraits, including those of the king and the principal figures of the court.
It is painted with the utmost precision, yet in a bold and masterly style, and there is a majestic solemnity in the arrangement of the whole, which suits well the grandeur of the subject.