Virginia Hall

Virginia Hall was an American who worked for the State Department in various European countries until 1939. When World War II broke out, she enlisted in the French ambulance corps in Paris, but managed to escape to Britain after France surrendered to Germany in June 1940. There, she was recruited by a spy working for the British government. After completing training, Hall adopted the disguise of a New York Post reporter and was sent back to Nazi-occupied France in August 1941.

Hall quickly built up a spy network and used a brothel to gather information from German troops. Eventually, she was sitting atop the Gestapo's most-wanted list and was chased out of France by Klaus Barbie, The Butcher of Lyon himself. She walked for three days across snow-covered mountains in the dead of winter to make her escape into Spain.

As if that weren’t enough for one war or lifetime, Hall wanted to return. Britain wouldn't allow her to cross French lines because of the target on her back, so she finally convinced her American homeland to do so. Posing as an old milkmaid, she went back to France in 1944 and this time, did even more damage to the German invaders. She called airdrops for resistance fighters, sabotaged trains, and blew up bridges all before the Allies even made it into France.

Oh, and she accomplished everything with only one leg; she'd lost her left leg below the knee to a hunting accident in 1933 and used a wooden prosthetic for the rest of her life. Hall was often called the "la dame qui boite" — the lady with the limp.

Shi Pei Pu

Shi Pei Pu was a male Chinese opera singer and playwright in the 1960s. After meeting a French embassy clerk, Bernard Boursicot, the two became fast friends. Under the guise of teaching him Chinese, Shi and Boursicot began meeting regularly, and that's when Shi told the naive Frenchman a fantastical tale. Shi was born a girl, but because her parents wanted a boy, they raised her as a boy. For Shi's whole life, because she lived in Chairman Mao's China, she could not risk being outed for lying about her identity. Men playing female parts in Beijing's opera was not uncommon, and because Shi was small, had delicate features, and had dressed and lived as a man, Boursicot did not suspect he was being lied to. The two began an affair, and eventually Boursicot began stealing embassy documents pertaining to the USSR that Shi could use to improve her standing in the Chinese Communist Party.

Bouriscot bounced around the globe, doing foreign service stints from Beijing to Paris to New Orleans to Mongolia. The first time he left China, perhaps as a means to secure her long-con honeypot, Shi told Bouriscot she thought she might be pregnant. When he returned two years later, she presented a picture of a little boy, whom Bouriscot wouldn't meet until the child was 7. But it was enough to keep him hooked, and though he had other relationships when he wasn't in Beijing, he always returned to Shi.

This ruse lasted for two solid decades. When Shi and Bouriscot were eventually arrested in Paris in 1983 and charged with espionage, Shi admitted that he was a man — and had been a man — the whole time.

Pearl Witherington

Pearl Witherington was born in Paris to British parents in 1914. When Germany invaded France in 1940, it took her family months to escape to Britain. Witherington started working for the British Air Ministry, but was determined to get her revenge on the Nazis.

In 1943, she joined Britain’s Special Operations Executive (SOE) and parachuted into occupied France to work as a courier posing as a cosmetics saleswoman. For the next few months, "Marie" smuggled weapons into France for the resistance and "harassed" German troops — meaning to exhaust or impede their forces.

In May 1944, her superior in the SOE network was caught and arrested by the Gestapo. Witherington, who then changed her code name to Pauline, took over his operation. Her team interrupted train lines some 800 times, preventing the German army from moving troops and supplies toward Normandy. She rallied and led a 3,000-person guerrilla network and saw the surrender of 18,000 German troops. Her campaign was so effective that the Nazis offered 1 million francs for her capture.

After the war, she continued living in France. She died in 2008 at the age of 93.

Sidney Reilly

Perhaps one of the best markers for a spy is how little is truly known about them. Around the turn of the century, a Russian-born British spy who went by the name of Sidney Reilly moved between regimes and behind enemy lines with surprising ease. He later became known as the "Ace of Spies," and was Ian Fleming's inspiration for his James Bond novels.

Details of his life have been obfuscated by myth and the occasional lack of hard evidence, but by most accounts, he was known for his charismatic personality, womanizing, and the ability to get into and out of the tightest of situations. During the Russo-Japanese War, he worked as a double agent for Britain and the Japanese Empire. During World War I, he provided detailed information about Germany’s naval development program. After the war, he went to Russia determined to take down Lenin (including participation in a failed assassination attempt) and the Bolshevik regime.

Eventually, in 1925, his cover was blown and he was arrested by Soviet officials. He was executed that November, but, of course, a lack of evidence allowed room for rumors that he'd escaped, defected, faked his death, or was perhaps just donning a new identity and was still working in the field.

Cher Ami

Cher Ami is the only non-human on this list, but no less deserving of recognition. During World War I, many military battalions still relied on carrier pigeons to get information back and forth. Unfortunately, pigeons were also very risky. Despite their small size and speed, they could be shot down by enemy gunners and their messages intercepted. In fact, gunners were trained to shoot down pigeons because they were so valuable.

On October 4, 1918, some 500 American soldiers found themselves pinned behind enemy lines. Things were looking dire as pigeon after pigeon was shot out of the sky. Since other American troops didn’t even know where they were, they were getting bombed by their own allies. There was only one pigeon left, named Cher Ami, and with it, the last hope of the soldiers in the "Lost Battalion." They attached a note that gave their location along with the friendly message regarding the bombardments: “For heaven’s sake, stop it.”

Cher Ami flew headfirst into enemy gunfire. He was shot through the chest just after takeoff, but managed to finish the 25-mile journey. When the allies read the message, they adjusted their artillery fire and saved the lives of 194 trapped American soldiers.

Cher Ami survived and was awarded the French Croix de Guerre, one of France’s highest military honors. He returned to the United States with his handler, and can now be seen (in stuffed version) at the Smithsonian Museum of American History.