Watch Movies2Watch. On Christmas Eve in 1818, parish assistant Joseph Mohr is on the road. Despite the freezing cold, he has just blessed a poor farming family and is now on his way back to Oberndorf near Salzburg. Once home, the assistant pastor puts his thoughts into a poem on this quiet night. His friend, the teacher and organist Gruber, is asked to compose a melody for it. The birth of the world's most famous Christmas carol.