The feast of the Queenship of Mary was established in 1954 by Pope Pius XII. The original date for this feast was chosen as May 31st, but was later moved to the octave day of the feast of the Assumption, August 22nd. This memorial celebrates the same event that is highlighted by the fifth glorious mystery or the Rosary.
Throughout the New Testament, Mary's role in heaven is mentioned. Mary is alluded to as Queen in the book of Revelations, and throughout the Bible. It is because of Jesus close relationship with his mother that she shares in his kingship.
The Church and the faithful for have also referred to Mary as queen since the fourth century. Various songs, litanies, and prayers refer to Mary as queen. (e.g. Regina Caeli during Eastertide.) The Church has affirmed the title of Mary in modern times through documents including Lumen Gentium (..."and exalted by the Lord as Queen over all things, that she might be the more fully conformed to her Son" Lumen Gentium 59) and the papal encyclical Ad Coeli Reginam.
The title Queen is used to indicate the final state of the Virgin, seated beside her Son, the King of glory.
Queen of Heaven rejoice, alleluia
The Son whom you merited to bear alleluia
Has risen as he said alleluia
Pray for us to God alleluia
Rejoice and be glad, O Virgin Mary, alleluia!
For the Lord has truly risen alleluia