For several years after his father's death, Christopher Tolkien worked on a Silmarillion narrative. He tried to use the latest writings of his father's and to keep as much internal consistency (and consistency with The Lord of the Rings) as possible, given the many conflicting drafts. He enlisted the help of the Canadian Guy Gavriel Kay, now the author of a fantasy trilogy inspired by Arthurian legend; Kay spent a year with him in Oxford editing the materials in secret. As explained in The History of Middle-earth, Christopher Tolkien drew upon numerous sources, relying on post-Lord of the Rings works where possible, ultimately reaching as far back as the 1917 Book of Lost Tales to fill in portions of the narrative that his father had planned to write but never addressed. In one later chapter of Quenta Silmarillion, "Of the Ruin of Doriath", untouched since the early 1930s, he had to construct a narrative practically from scratch. Christopher Tolkien commented that, had he taken more time and had access to all the texts, he might have produced a substantially different work. In his foreword to The Book of Lost Tales 1 in 1983, he wrote that
