Below you’ll find some background information, from The United Methodist Book of Worship, that I normally print in the bulletin for the service of Lessons and Carols. I forgot to put it in this year, so I’m posting it here:
In 1880 E. W. Benson, then Anglican Bishop of Truro, England, composed a Festival of Nine Lessons and Carols, based on ancient sources, for Christmas Eve. In 1918 it was adapted for the chapel of King’s College, Cambridge, by its Dean, Eric Milner-White, who also wrote The Bidding Prayer. The Blessing after The Lord’s Prayer, added by Milner-White, was first included in its present form in 1930. The service has been edited for United Methodist congregations [and further adapted for this congregation]. 
 United Methodist Church, The United Methodist Book of Worship (Nashville, TN: United Methodist Publishing House, 1992), 284.