The "O Antiphons" were first used by the Church in the 8th and 9th centuries. They are based on various titles used for the Christ and are scripturally-based short prayers used from the 17th to the 23rd of December. In the Roman Catholic Church they are the antiphons for the Vespers in the Office of the Day. In these "O Antiphons" the Church expresses her deep longing for the coming of the Messiah. The Advent hymn "O Come, O Come, Emmanuel" is based on the "O Antiphons" and was written sometime during the 9th Century.