Catholic Encyclopedia (1913)/Feast of the Expectation of the Blessed Virgin Mary
Expectation of the Blessed Virgin Mary (Exspectatio Partus B. V. M.), Feast of the, celebrated on December 18 by nearly the entire Latin Church. Owing to the ancient law of the Church prohibiting the celebration of feasts during Lent (a law still in vigor at Milan), the Spanish Church transferred the feast of the Annunciation from March 25 to the season of Advent, the Tenth Council of Toledo (656) assigning it definitely to December 18. It was kept with a solemn octave. When the Latin Church ceased to observe the ancient custom regarding feasts in Lent, the Annunciation came to be celebrated twice in Spain, viz. March 25 and December 18, in the calendars of both the Mozarabic and the Roman Rite (Missale Gothicum, ed. Migne, pp. 170, 734). The feast of December 18 was commonly called, even in the liturgical books, "S. Maria de la O", because on that day the clerics in the choir after Vespers used to utter a loud and protracted "O", to express the longing of the universe for the coming of the Redeemer (Tamayo, Mart. Hisp., VI, 485). The Roman "O" antiphons have nothing to do with this term, because they are unknown in the Mozarabic Rite. This feast and its octave were very popular in Spain, where the people still call it "Nuestra Senora de la O". It is not known at what time the term Expectatio Partus first appeared; it is not found in the Mozarabic liturgical books. St. Ildephonsus cannot, therefore, have invented it, as some have maintained. The feast was always kept in Spain and was approved for Toledo in 1573 by Gregory XIII as a double major, without an octave. The church of Toledo has the privilege (approved April 29, 1634) of celebrating this feast even when it occurs on the fourth Sunday of Advent. The "Expectatio Partus" spread from Spain to other countries; in 1695 it was granted to Venice and Toulouse, in 1702 to the Cistercians, in 1713 to Tuscany, in 1725 to the Papal States. The Office in the Mozarabic Breviary is exceedingly beautiful; it assigns special antiphons for every day of the octave. At Milan the feast of the Annunciation is, even to the present, kept on the last Sunday before Christmas. The Mozarabic Liturgy also celebrates a feast called the Expectation (or Advent) of St. John the Baptist on the Sunday preceding June 24.
F. G. HOLWECK