You will conceive in your womb and bear a son, and you shall call his name Jesus. He will be great and will be called the Son of the Most High; the Lord God will give him the throne of his father David, he will reign eternally over the house of Jacob, and his kingdom will have no end, we read in the Gospel of the Mass.
Mary's kingship is intimately related to that of her Son. Jesus Christ is King because he has full and complete power, both in the natural and supernatural order; this kingship, besides being full, is proper and absolute. Mary's kingship is full and participatory of that of her Son. The terms Queen and Lady applied to the Virgin are not a metaphor; with them we designate a true pre-eminence and an authentic dignity and power in heaven and on earth. Mary, because she is the Mother of the King, is truly and properly Queen, standing at the summit of creation and being effectively the first human person in the universe. She, "most beautiful and most perfect, has such fullness of innocence and holiness that no greater one can be conceived after God, and that outside of God no one can ever comprehend".
The titles of Mary's kingship are her union with Christ as Mother as announced to her by the Angel and her association with her Son King in the redemptive work of the world. By the first title, Mary is Mother Queen of a King who is God, which exalts her above all other human creatures; by the second, Mary Queen is dispenser of the treasures and goods of the Kingdom of God, by reason of her co-redemption.
At the institution of this feast, Pius XII invited all Christians to approach this "throne of grace and mercy of our Queen and Mother to ask her for help in adversity, light in darkness, relief in pain and sorrow", and encouraged all to ask the Holy Spirit for graces and to strive to abhor sin, to free themselves from its slavery, "so that they may render constant vassalage, perfumed with the devotion of children", to her who is Queen and so great a Mother. Adeamus ergo cum fiducia ad thronum gratiae, ut misericordiam consequamur.... Let us therefore approach the throne of grace with confidence, so that we may obtain mercy and find the grace to help us at the right moment10. This throne, symbol of authority, is that of Christ, but he wanted it to be in his Mother, the throne of grace, where we can more easily attain mercy, since she was given to us "as the advocate of grace and Queen of the universe".
Today we contemplate the great feast of Heaven in which the Most Blessed Trinity goes out to meet Our Mother, already assumed into Heaven for all eternity. "It is right that the Father and the Son and the Holy Spirit crown the Virgin as Queen and Mistress of all creation.
"Take advantage of this power and, with filial boldness, join in this feast of Heaven. -I, the Mother of God and my Mother, crown her with my purified miseries, because I have no precious stones or virtues.
"Cheer up!"12. She waits for us; she wants us to join in the joy of the saints and the angels. And we have the right to participate in such a great feast, for she is our Mother.