教宗庇護十二世在 1954 年定下日子讓教會慶祝聖母為天地元后。這紀念日本在五月三十一日，到 1970 年被改為聖母升天後的第八日。
Pope Pius XII established this feast in 1954 to celebrate Mary as the Queen of Heaven. Initially the feast day was on May 31st. In 1970 it's been changed to the octave day of the Assumption.
In Pope Pius XII's 1954 encyclical, he pointed out that Mary deserves the title because of several reasons: she is the Mother of God, she participated closely with Jesus in His redemptive work, and because of her preeminent perfection and intercessory power.
Mary's queenship has biblical roots. In the gospel according to Luke, during the annunciation, the angel Gabriel prophesied that Mary will bear a son, and "He will be great and will be called Son of the Most High, and the Lord God will give him the throne of David his father, and he will rule over the house of Jacob forever, and of his kingdom there will be no end." Then when Mary went to greet Elizabeth, Elizabeth was filled with the Holy Spirit and said to her, "Most blessed are you among women, and blessed is the fruit of your womb. And how does this happen to me, that the mother of my Lord should come to me? For at the moment the sound of your greeting reached my ears, the infant in my womb leaped for joy. Blessed are you who believed that what was spoken to you by the Lord would be fulfilled." As Jesus is the king of the everlasting kingdom, then it is logical to follow that His mother Mary is crowned as queen after the Assumption into heaven.
Dear Lord, help us follow Mary in her footsteps, to become a disciple of Jesus Christ who submits totally and humbly to God's will.
Hail Mary, full of grace. Our Lord is with thee. Blessed art thou among women, and blessed is the fruit of thy womb, Jesus. Holy Mary, Mother of God, pray for us sinners, now and at the hour of our death. Amen.