24. We wish also to recall that Our predecessor of immortal memory, Sixtus IV, touched favorably upon the doctrine of the Immaculate Conception of the Blessed Virgin, beginning the Apostolic Letter Cum praeexcelsa³⁰ with words in which Mary is called "Queen," "Who is always vigilant to intercede with the king whom she bore." Benedict XIV declared the same thing in his Apostolic Letter Gloriosae Dominae, in which Mary is called "Queen of heaven and earth," and it is stated that the sovereign King has in some way communicated to her his ruling power.³¹