This hymn text was written by St. Theodulph of Orleans in 820 while he was imprisoned in Angers, France, for conspiring against the King, with whom he had fallen out of favor. The text acts as a retelling of the triumphal entry of Jesus into Jerusalem. The medieval church actually re-enacted this story on Palm Sunday using a standard liturgy that featured this hymn. The priests and inhabitants of a city would process from the fields to the gate of the city, following a living representation of Jesus seated on a donkey. When they reached the city gates, a choir of children would sing the hymn, then in Latin: Gloria, laus et honor, and the refrain was taken up by the crowd. At this point the gates were opened and the crowd made its way through the streets to the cathedral. Though we might not have any city gates to proceed through today, this hymn still acts as a royal hymn of praise and proclamation.
Our church members, as so many do on Palm Sunday, sing this hymn as we enter the sanctuary waving our palm branches. Notice the middle picture on the right. Later in the service this youngster is waving two branches in time with the music, looking very much like part of the audience at a rock concert.
Our current church does not do the palm branches on Palm Sunday or sing this hymn. I miss that! Nice to see it in your church though. Good collage! I guess I'll have to find it on YouTube next year!