Taking from Vatican II’s Lumen Gentium #36, John Paul II pinpoints the anthropology of kingship by the act of self-mastery in order to serve. In the case of Christ, the self-mastery took the form of “the Logos adopt(ing) the being of the man Jesus into his own being and speak(ing) of it in terms of his own I: `For I have come down from heaven, not to do my own will, but the will of him who sent me’ (Jn. 6, 38). In the son’s obedience, where both wills become one in a single Yes to the will of the Father, communion takes place between human and divine being.” Jesus Christ is King because he took the human will of Jesus of Nazareth as his own, and, having been made sin(2 Cor. 5, 21), subdued it. That act of the divine Person mastering his own human will is the establishment of kingship. It is also the supreme manifestation of freedom. John Paul II remarked: “The Crucified Christ reveals the authentic meaning of freedom; he lives it fully in the total gift of himself and calls his disciples to share in his freedom.” (Veritatis Splendor #85). To be king is to be master of oneself. Again, John Paul II said, “This dignity is expressed in readiness to serve, in keeping with the example of Christ, who `came not to be served but serve.’ If, in the light of this attitude of Christ’s, `being a king’ is truly possible only by `being a servant,’ then `being a servant’ also demands so much spiritual maturity that it must really be described as `being a king.’ In order to be able to serve others worthily and effectively we must be able to master ourselves, possess the virtues that make this mastery possible. Our sharing in Christ’s kingly mission – His `kingly function’ (munus) – is closely lined with every sphere of both Christian and human morality.”
In the case of our Lady, “the Mother of Christ is glorified as `Queen of the Universe.”  She is so because she too mastered and subdued her own will. “She who at the Annunciation called herself the `handmaid of the Lord’ remained throughout her earthly life faithful to what this name expresses. In this she confirmed that she was a true `disciple’ of Christ, who strongly emphasized that his mission was one of service: the Son of Man `came not to be served but to serve, and to give his life as a ransom for many’ (Mt. 20, 28). In this way Mary became the first of those who, `serving Christ also in others with humility and patience lead their brothers and sisters to that King whom to serve is to reign,’ and she fully obtained that `state of royal freedom’ proper to Christ’s disciples: to serve means to reign!”
Also, now, Mary continues to exercise her Queenship insofar as she continues to make the gift of herself in engendering the Body of Christ (us): “A woman clothed with the sun, and the moon was under her feet, and upon her head a crown of twelve stars. And being with child, she cried out in her travail and was in the anguish of delivery…And she brought forth a male child, who is to rule all nations with a rod of iron; and her child was caught up to God and to his throne” (Apocalypse 12, 2, 5). John Paul continues, “The glory of serving does not cease to be her royal exaltation: assumed into heaven, she does not cease her saving service, which expresses her maternal mediation `until the eternal fulfillment of all the elect.”
 Josef Ratzinger, “Behold the Pierced One,” Ignatius (1986) 92.
 John Paul II, Redemptor Hominis, #21.
 John Paul II, Redemptoris Mater #41.