Harry Turtledove

Harry Norman Turtledove (born June 14, 1949) is an American author. He is best known for his works about alternate history, historical fiction, fantasy, science fiction, and mystery fiction. 
His "Worldwar" series received a Sidewise Award for Alternate History Honorable Mention in 1996. In 1998, his novel "How Few Remain" won the Sidewise Award for Alternate History. He won his second Sidewise Award in 2003 for his novel "Ruled Britannia". He won his third Sidewise Award for his short story "Zigeuner."