A student of historian Norman Davies and a regular public speaker and commentator for the press and TV, he is the author of books including "Killing Hitler" and "The Devils' Alliance".
His latest book project, "First To Fight: The Polish War 1939", concentrates on the little-known subject of the September Campaign - the opening act of World War II in Europe.
Talking to Polish Radio's Adam Dąbrowski during the launch of the Polish translation of the book, Roger Moorhouse explained that the September Campaign was a crucial phase which is all too often overlooked by Western historians. And he hopes that his book will change that.