Joseph Mohr was walking through the woods one winter in 1816 when the words of Stille Nacht came to him.

As the Austrian vicar enlisted the help of church organist Franz Xaver Gruber to set the words to music, Joseph didn't know that they were composing what was to become the world's third all-time best-selling single.

The original Christmas truce

It was almost a hundred years later that English and German troops would sing the song as they held a Christmas truce during World War 1. It was the only carol that both sides knew the words to.

Image copyright: Holly Thomas