"AVE REGINA CAELORUM". — It is the second of the four great Marian Antiphons, recited after the Divine Office from February 3 until Holy Thursday. Its author is unknown, but it cannot be later than the 12th century, since it is already found in manuscripts of that time. A characteristic of this period, in fact, is its metrical structure (medieval arithmetical rhythm): the octonaries, freed from the rules of quantity and also, the first and seventh, from the norms of accent, form two strophes with alternating rhyme (a, a; b, b). The two quatrains, lively and joyful, celebrate the heavenly royalty of Mary and her incomparable inner beauty, while recalling the part the Virgin played in human Redemption.
Having entered the liturgy as early as the 13th century, its first verse provided the opening for other medieval hymns (cf. U. Chevalier, Repert. Hymnal., Paris 1893; the collections of Mone and Dreves). Clement VI, who in 1350 introduced the four Marian Antiphons into the Roman clergy's office, assigned it to the period after Pentecost (from Trinity Sunday to Advent); the period from the Purification to Easter was reserved for the Salve Regina. Their place, however, was changed in 1568 by the reform of Pius V, which is still in force.