In the first of a two-part series, historian Dan Snow examines how two years of meticulous planning, espionage and the analysis of millions of three-dimensional aerial photographs helped the Allied Forces gain a foothold in northern France.
In the first of a two-part series, historian Dan Snow examines how two years of meticulous planning, espionage and the analysis of millions of three-dimensional aerial photographs helped the Allied Forces gain a foothold in northern France.