How old was J.R.R Tolkien when he started writing books?

J.R.R. Tolkien started writing stories at a young age, but he didn't publish his first book, The Hobbit, until he was 45 years old.

He began writing the stories that would later form the basis for The Lord of the Rings in his early 20s, but it wasn't until he was in his late 30s and early 40s that he truly began working on them in earnest.