Today the carol is represented almost exclusively by the Christmas carol, the Advent carol, and to a much lesser extent by the Easter carol, however despite their present association with religion, this has not always been the case.
The word carol is derived from the Old French word carole, a circle dance accompanied by singers (in turn derived from the Latin choraula). Carols were very popular as dance songs from the 1150s to the 1350s, after which their use expanded as processional songs sung during festivals, while others were written to accompany religious mystery plays (such as the Coventry Carol, written in 1591).
Following the Protestant Reformation (and the banning of many religious festivities during the British Puritan Interregnum), carols went into a decline due to Calvinist aversion to "nonessential" things associated with Roman Catholicism. However, composers such as William Byrd composed motet-like works for Christmas that they termed carols; and folk-carols continued to be sung in rural areas. Nonetheless, carols did not regain their former popularity until a revival in the 19th century when many surviving non-religious carols were re-discovered and arranged for church use with new Christian lyrics.
In modern times, songs that may once have been regarded as carols are now classified as songs (especially Christmas songs), even those that retain the traditional attributes of a carol - celebrating a seasonal topic, alternating verses and chorus, and danceable music.
Some writers of carols, such as George Ratcliffe Woodward who wrote Ding Dong Merrily on High and William Morris who wrote Masters in this Hall, reverted to a quasi-mediaeval style; this became a feature of the early twentieth century revival in Christmas Carols.
Some composers have written extended works based on carols. Examples include Benjamin Britten (A Ceremony of Carols), Ralph Vaughan Williams (Fantasia on Christmas Carols) and Victor Hely-Hutchinson (Carol Symphony).