As in all the mysteries of Mary’s life, Mary is closely associated with Jesus: Her queenship is a share in Jesus’ kingship, and when it comes to her queenship, we can go all the way back to the Old Testament to see why it’s true: in the Old Testament the mother of the king has great influence in court. All the things we know about the Blessed Virgin Mary always flows from what we know about the Lord Jesus Christ.
As early as in the fourth century, St. Ephrem called Mary “Lady” and referred to her as “Queen.” Later Church fathers and doctors continued to use the title. Hymns of the 11th to 13th centuries address Mary as queen: “Hail, Holy Queen,” “Hail, Queen of Heaven,” “Queen of Heaven.” The Church’s devotional life reflects our belief: one of the mysteries of the Rosary, for instance, is the crowning of Mary as Queen of Heaven. In several of the Church’s prayers and litanies, the Blessed Virgin is assigned the title of Queen.
The feast is a logical follow-up to the Assumption and is now celebrated on the octave day of that feast. In 1954, Pope Pius XII established this feast, and he wrote an encyclical titled “To the Queen of Heaven.” In that encyclical, the Pope teaches that Mary deserves the title of Queen because she is Mother of God, and because she is closely associated with Jesus' redemptive work as the New Eve. As Queen, the Blessed Virgin Mary shows us the highest state of perfected humanity, and she intercedes for us in our own growth in holiness.
Grant us, O merciful God, protection in our weakness: That we who celebrate the memory of the holy Mother of God, Our Lady Queen of Heaven, may, by her intercession, be delivered from our sins; through Jesus Christ thy Son our Lord, who liveth and reigneth with thee in the unity of the Holy Ghost ever, one God world without end. Amen.