Portrait of Infante Ferdinand of Spain, c1574. Ferdinand of Spain (1571-1577) was the son of Philip II of Spain and a half-brother of Archduchess Isabella. Ferdinand still wears a skirt, so he must be no more than about four years old. Coello trained in Brussels and spent much of his career in Philips service. A portrait by Coello of Ferdinand in a green coat with a pet bird was in the kings estate; this is that painting or a version made for a relative such as Isabella.