O Come, All Ye Faithful: the story behind the carol

The Latin hymn "Adeste Fideles" survives in manuscripts copied by John Francis Wade, an English Catholic living in France in the 1740s; whether he wrote it or copied an older hymn is still debated.

Frederick Oakeley, an Anglican priest who later became Catholic, translated it into English in 1841. It's now the traditional opening hymn of many Christmas services.