On February 1, 1584, Pedro Moya de Contreras, archbishop of Mexico City, dispatched the official summons to the bishops of his ecclesiastical province to attend the Third Mexican Council set for the ninth of December of that same year. At the request of the bishop of the distant diocese of Guatemala, Fray Fernando Gómez de Córdoba, of the Order of St. Jerome, the opening date was postponed to January 20, 1585.
One of the Archbishop's letters of convocation was addressed to the first bishop of the Philippines, Fray Domingo de Salazar, Dominican. From Salazar's reply we know that the Archbishop did not insist on his personal attendance nor did he even suggest that he send a delegate. The purpose of the letter was to inform Salazar of the convocation of the Council and invite him to send a written report on conditions of the Church in the Islands, and propose such problems as he thought the assembled bishop should discuss and strive to solve.