What was the first published book illustrated by J.R.R. Tolkien himself?

The Hobbit was the first published book illustrated by J.R.R. Tolkien himself.

Tolkien supplied illustrations, maps, and decorative designs for The Hobbit, helping establish the visual character of his invented world. The first edition included a frontispiece, several black-and-white pictures, and maps associated with the journey to the Lonely Mountain.

His artwork was not merely ornamental. Tolkien used images to clarify geography, architecture, lettering, and atmosphere, and his drafts show how closely visual design was connected to his storytelling. The dust jacket for the first edition was also based on his own design.

Later Tolkien books also appeared with his illustrations or facsimiles of his artwork, but The Hobbit was the first of his published books to present his drawings to readers. The Lord of the Rings included maps and decorated elements, yet its publication history and illustration program were different. Tolkien’s art therefore forms an important part of the original presentation of Bilbo’s adventure.