Christmas carols are extremely old and are thought to have originated circa 1350 to 1550.
The world carol or carole is medieval and originated from French or Anglo-Norman.
It is widely thought to mean a dance song or circle dance accompanied by singing.
Carols were first sung as pagan songs at the Winter Solstice celebrations as people danced round stone circles. The Winter Solstice is the shortest day of the year and usually takes place around Dec 21. (You can find out more about this here)
They used to be written and sung during all four seasons but only the tradition of singing them at Christmas has really survived.
Silent Night, composed in 1818 by Franz Xaver Gruber in the small town of Obernforf in Salzburg is generally held to be the world’s most popular Christmas carol. The town was delcared an important cultural heritage site by UNESCO in March 2011.