Elroy Dale

 was a patron of Diana Wright. He liked reading fiction books. He wanted to join the war. (AUDIO: The Bookshop at the End of the World)

The Doctor would eventually discover that Elroy, along with many other people throughout history who looked like him, were caused by a group of Time War Daleks who — while on a mission to prevent the rise of Time Lord society on Gallifrey — created a time distortion which created alternate versions of themselves as four un-mutated Kaled people. This time distortion also caused there to be multiple copies of these four Kaleds at various points throughout time and space. (AUDIO: Effect and Cause)