It is one of the four seasonal Marian antiphons of the Blessed Virgin Maryprescribed to be sung or recited in the Liturgy of the Hours at the conclusion of the last of the hours to be prayed in common that day, typically night prayer Compline or Vespers. Any one of these four or of other suitable antiphons may now be sung at any time of the liturgical year.
As with many Christian prayers, it takes its Coeli latino dating from its incipit or first word "Coeli latino dating." The Latin word coelummeaning "heaven" hence the English word celestialwas a common medieval and early modern spelling of caelumwhich was the only form in Classical Latin.
While the authorship of the Regina Caeli is unknown, the hymn has been traced back to the 12th century. It was in Franciscan use, after Compline, in the first half of the following century. According to Catholic tradition, St Gregory the Great heard angels chanting the first three lines one Easter morning in Rome, while following barefoot in a great religious procession of the icon of the Virgin painted by Luke the Evangelist.
He was thereupon inspired to add the fourth line. There are plainsong melodies a simple and an ornate form associated with Regina Caelithe official or "typical" melody being found in the Vatican Antiphonary, p.