Leblanc was born on May 22, 1915, in Neufchâteau, Belgium. During the Nazi occupation of Belgium (1940-1944), Leblanc was a member of the local underground resistance movement as an officer in the “Ardense Jagers” division. He was never caught, due mostly to the fact he spoke German. Immediately following the liberation of Belgium by Allied forces he started his own company publishing romance novels and movie magazines which was very profitable.