Diego de Castilla

Diego de Castilla (1510/15-1584), dean of Toledo Cathedral. Castilla was of Jewish blood, and this was a major issue, since in 1547, the then-archbishop of Toledo had passed a statute of cleanliness of blood, excluding from ecclesiastical office and benefices anyone with a trace of Jewish lineage over four generations. Therefore, Castilla developed an obsession for genealogy, working tirelessly to prove his family's links to Spain's medieval kings.

On 2 July 1577, El Greco was formally engaged by Diego de Castilla to paint three altarpieces for the Cistercian convent of Santo Domingo el Antiguo. He also signed contracts for the renowned El Espolio. El Greco was a friend of Luis de Castilla, son of the dean. No less significant was his second commission to El Greco for nine paintings for a funerary chapel that he had recently built alongside the Cistercian convent of Santo Domingo el Antiguo. Here, the artist would produce side panels depicting the Adoration of the Shepherds and the Resurrection, while the main altarpiece included images of the Assumption of the Virgin and The Trinity, subjects of central theological importance. Mark Irving regards these commissions as "a public declaration that he, a leading national figure in the battle against the Protestant heresy, could be trusted to support the theological argument of the Catholic church".