Sometimes the missives would arrive by post, with return addresses like “Cliff House, North Pole,” or “On Sleigh.” Or they’d be left in the house (“By Elf Messenger”). The look was never the same, but the envelopes were always colorful and meticulously lettered, the notes and elaborate drawings inside even more so. This went on for more than 20 years, until the youngest of the four recipients had, well, aged out. But looking now at J. R. R. Tolkien’s Letters from Father Christmas, collected and reproduced in a beautiful centenary edition in time for the holidays, it’s hard to think that anyone could ever outgrow them.

When Tolkien wrote most of the Father Christmas letters to his children—John, Michael, Christopher, and Priscilla—he was an Oxford professor, his fame still ahead of him (the letters spanned 1920–1943, while the Lord of the Ringstrilogy would not be published until the 50s). The letters are charming, full of fun, humor, joy, and imagination. Most are signed by Father Christmas, but Tolkien wrote some in the character of an elf assistant, Ilbereth—different handwriting, of course—and others as the recurring foil North Polar Bear, who also enjoys annotating Father Christmas’s letters in the margins (“ROT,” “STUPID JOKE,” “BAD rhyme! That’s beaten you!”). The longer letters give Tolkien space to spin stories and dispense useful information, such as “Goblins are to us very much what rats are to you, only worse because they are very clever.”