Christopher Tolkien, the son of Lord of the Rings author J.R.R. Tolkien has died. The Tolkien Society announced his passing on Thursday, January 16, 2020. He was 95 years old.

“Christopher’s commitment to his father’s works have seen dozens of publications released, and his own work as an academic in Oxford demonstrates his ability and skill as a scholar,” Tolkien Society Chair Shaun Gunner said in a statement. “We have lost a titan and he will be sorely missed.”

Tolkien was his father’s literary executor, editing much of the work that was published after the elder Tolkien’s death. He also created the detailed maps of Middle-earth that readers have used for reference material while reading the epic fantasy series.

Born in Leeds, England, Tolkien grew up in Oxford and joined the Royal Air Force during World War II. He later became a lecturer at the University of Oxford and was known for being an expert on his father’s work. After his father’s passing, Tolkien worked on his father’s unpublished manuscripts, including The Silmarillion, which provides the origins of Middle-earth. His work on his father’s writing included editing and overseeing publication of 24 editions.