Trivia

The main character, O'Hara, is based on the real-life adventurer Morris "Two-Gun" Cohen (1887-1970). Born in Poland to a Jewish family, Cohen grew up in the tough streets of London's East End. As a teenager, he moved to western Canada and became a ranch hand and gambler in Saskatchewan, and later a highly successful real-estate agent in Alberta. During World War I he fought in Europe with the Canadian Railway Troops. His friendship with Chinese workers on the Canadian-Pacific Railroad prompted him to go to China in the 1920s. After negotiating a railroad deal with Dr. Yat-sen Sun, Cohen became a personal bodyguard to Sun and a trainer of Sun's private army. After Sun's death in 1925, Cohen ran guns for various Chinese warlords throughout the 1930s. When the Japanese invaded China in 1937, Cohen continued to supply Chinese resistance forces with arms and served with the British SOE. In 1941, following the fall of Hong Kong, he was captured by the Japanese and put in a prison camp, but was traded to the English in 1943 in a rare prisoner exchange. After the war, Cohen continued to operate in China as an agent for various British firms, including Rolls-Royce and Decca Radar. His former dealings with Chinese warlords kept him in good standing with Chinese Communist officials until his death in 1970.

Akim Tamiroff (General Yang) received one of his two Oscar nominations for this film. Tamiroff's second nomination was for another Gary Cooper film, "For Whom the Bell Tolls."

Gary Cooper later regretted starring in this film.

Future novelist John O'Hara made his only acting appearance as a reporter on a train. Twenty-two years later Gary Cooper would star in the screen adaptation of O'Hara's novel Ten North Frederick (1958).

The title was spoofed in the Warner Bros. cartoon The Major Lied 'Til Dawn (1938).