A short acclamation of praise to the Trinity. "Glory to the Father, and to the Son, and to the Holy Spirit: as it was in the beginning, is now, and will be for ever. Amen." The term is from the opening words of the acclamation in Latin. Gloria Patri is also known as the "Lesser Doxology," distinguishing it from the Gloria in excelsis, the "Greater Doxology." It may have been influenced by the trinitarian baptismal formula of Mt 28:19.
Gloria Patri is always sung or said at the conclusion of the entire portion of the Psalter at Morning Prayer, Noonday Prayer, Evening Prayer, and Compline. It may be used after the invitatory psalm or the canticle "Christ our Passover" at Morning Prayer; and after each psalm, and after each section of Ps 119 at Morning and Evening Prayer (BCP, p. 141). Gloria Patri is used in the BCP to conclude Canticles 3, 4, 5, 8, 9, 10, 11, 15, 16, 17, and 19. It is also used to conclude the Magnificat and the Nunc dimittis in Evening Prayer. Gloria Patri may be omitted after these canticles. It follows the opening versicle and response at Morning Prayer, Noonday Prayer, and Evening Prayer. It follows the confession of sin and a versicle and response from Ps 70:1 at Compline. This pattern of versicle and response is based on the model for the beginning of the Daily Offices prescribed by St. Benedict of Nursia (c. 480-c. 550). Gloria Patri is also used with verses from Ps 44 at the opening of the Supplication. An alternative pointing of the Gloria Patri is provided by the BCP (p. 141). In Rite 1 services of Morning Prayer and Evening Prayer, it is permissible to use the form "Glory be to the Father, and to the Son, and to the Holy Ghost: As it was in the beginning, is now, and ever shall be, world without end. Amen."
Gloria Patri was traditionally used to provide a climax and cut-off for psalms that "covered" liturgical actions such as the procession at the entrance of the clergy, the presentation of the oblations, and the communion of the people. A signal would be given when the liturgical action was completed, and the psalm would then end with Gloria Patri. It was not used with gradual psalms or tracts, since these texts were understood to have their own integrity in the service. This tradition continues in modern practice. Gloria Patri is seldom used after the gradual psalm at the eucharist.
Glossary definitions provided courtesy of Church Publishing Incorporated, New York, NY,(All Rights reserved) from “An Episcopal Dictionary of the Church, A User Friendly Reference for Episcopalians,” Don S. Armentrout and Robert Boak Slocum, editors.