Which Tolkien work is a collection of letters written in the voice of Father Christmas?

The Father Christmas Letters is Tolkien’s collection of letters written in the voice of Father Christmas.

Tolkien created the letters for his children between 1920 and 1943. Each Christmas, the children received a letter supposedly sent from the North Pole, often featuring adventures, mishaps, and illustrations. Tolkien developed recurring figures and events, including the North Polar Bear, whose humorous mistakes create problems for Father Christmas.

The letters were published posthumously in 1976, edited by Baillie Tolkien, Tolkien’s daughter-in-law. The book is separate from Tolkien’s Middle-earth legendarium, although it demonstrates the same combination of invented languages, maps, drawings, and detailed imaginary history. It is sometimes confused with Tolkien’s scholarly or fictional works because it was published as a substantial illustrated book, but its original purpose was a private family Christmas tradition.