8 From early times Christians have believed, and not without reason, that she of whom was born the Son of the Most High received privileges of grace above all other beings created by God. He "will reign in the house of Jacob forever," "the Prince of Peace," the "King of Kings and Lord of Lords." And when Christians reflected upon the intimate connection that obtains between a mother and a son, they readily acknowledged the supreme royal dignity of the Mother of God.
Source: Ad Caeli Reginam (Vatican.va)