In March 1941, after a year of devastating U-boat attacks, the British War Cabinet turned to an intensely private, bohemian physicist named Patrick Blackett to turn the tide of the naval campaign. Though he is little remembered today,...

Queen Elizabeth I and England's First Spymaster Sir Francis Walsingham's official title was principal secretary to Queen Elizabeth I, but in fact this pious, tight-lipped Puritan was England's first spymaster. A ruthless, fiercely lo...