Born just two weeks apart in 1874, Winston Churchill and William Lyon Mackenzie King had much in common. Both forged long parliamentary careers, and each led his country to victory in World War II. A BBC poll deemed Winston Churchill the greatest Briton of all time, and Mackenzie King has been judged by a group of historians as the greatest Canadian prime minister. Their parallel careers fostered a working relationship that lasted almost fifty years. It was not always an easy relationship, however. Churchill, famous for his drink and cigars, was impetuous and charismatic, an extrovert; King, a teetotaller during WWII, was noted for considering all options before cautiously proceeding. Fate threw this ill-matched pair together. For the first time, the vital relationship between these two very different men is explored in depth. It is the story not just of two extraordinary leaders, but also of the changing bonds between Britain and Canada.