Brief History of the Gloria in Excelsis Deo

 

The hymn – Great Doxology – begins with the words that the angels sang when the birth of Christ was announced to shepherds in Luke 2:14. Other verses were added very early, forming a doxology, which in the fourth century became part of morning prayer, and is still recited in the Byzantine Rite Orthros service.

The Latin translation is traditionally attributed to St. Hilary of Poitiers (c. 300-368), who may have learned it while in the East (359-360). The Vulgate Latin translation of the Bible was commissioned only in 382. The Latin hymn thus uses the word excelsis to translate the Greek word ὑψίστοις (the highest) in Luke 2:14, not the word altissimis, which St. Jerome preferred for his translation. In the Roman Rite, it is recited during Mass. 

In the Tridentine Mass, the priest is instructed, when saying the opening phrase "Gloria in excelsis Deo", to extend his hands and raise them to shoulder height and, at the word "Deo", to join them and bow his head. He is then to continue the recitation standing erect with hands joined and bowing his head to the cross at the words "Adoramus te", "Gratias agimus tibi", "Iesu Christe" (twice), and "Suscipe deprecationem nostram", and at the concluding phrase (as also at the concluding phrase of the Nicene Creed and the Sanctus), to make a large sign of the cross on himself. At High Mass  the priest intones the opening phrase, while the deacon and subdeacon stand behind him; then they join him at the altar and together with him quietly recite the rest of the hymn, after which they sit down and wait for the choir to finish its singing of the same text.