"A Kingdom for a Sword was originally a piece of Diablo fanfic that I rewrote in progress to be set in my Road of Legends universe. When I approached Pocket Books to try to get a Diablo book to write, it was one of the writing samples I sent in. Looking back at it, it's not bad, with the exception of the final paragraph, which is absolutely terrible (let's just say that it was not written from a point of maturity)."— Robert B. Marks(src)
A Kingdom for a Sword originally began as a piece of Diablo fanfiction, though impressed Marks' editor enough to give him an E-book contract. In the end, it was revamped and placed into Marks' own Road of Legends universe. However, A Kingdom for a Sword possesses many similarities with Demonsbane, as per Marks' own admission.