History's Most Famous Traitors

History doesn't always reward loyalty. Across centuries, alliances shattered, loyalties flipped, and power changed hands—some in silence, and others with a blade. Some names left behind more than just scandal—they became shorthand for betrayal itself. As you read on, you might see just how easily trust can vanish under the weight of ambition. Here are 20 figures whose betrayals we'll never forget. 

Random Institute on Unsplash

1. Benedict Arnold

Few names in American history sting like Benedict Arnold’s. Once a celebrated general, he schemed to surrender West Point to the British in 1780. After escaping to England, he became the ultimate symbol of betrayal. Today, his name is synonymous with betrayal in the U.S.

Thomas Hart on Wikimedia

2. Vidkun Quisling

As World War II raged, Vidkun Quisling willingly ruled Norway under Nazi command, and his puppet government betrayed the people for power. Executed in 1945 for treason, his name became a global slur. Even now, calling someone a “Quisling” brands them as the lowest kind of traitor.

Riksarkivet (National Archives of Norway) on Wikimedia

3. Robert Hanssen

He remains one of the most dangerous—and skilled—traitors in American espionage history. Robert Hanssen fooled the FBI for over two decades while spying for Soviet and Russian intelligence. His betrayal caused extraordinary damage to national security. Caught in 2001, he received life without parole. 

Federal Bureau of Investigation (FBI) on Wikimedia

4. Mir Jafar

In South Asia, his name doesn’t need explaining as it’s shorthand for betrayal and treachery. During a pivotal moment in 1757, Mir Jafar aided British forces against the Nawab of Bengal. This led to the British rewarding him with power, but the public never forgave him. 

Francis Hayman on Wikimedia

5. Klaus Fuchs

Klaus Fuchs sat among trusted scientists, all while secretly passing atomic research to Soviet agents. Western allies believed in him until 1950, when his arrest shattered that illusion. His 14-year sentence marked one of history’s most damaging breaches in nuclear security circles.

The National Archives UK on Wikimedia

6. Marcus Junius Brutus

Once a trusted confidant, he turned against his mentor. In the heart of Rome’s political drama, Brutus joined the plan to get rid of Julius Caesar in 44 BCE. Not only was he seen as a traitor, but Shakespeare sealed that image in timeless literary betrayal.

Soerfm on Wikimedia

7. Wang Jingwei

Wang Jingwei wore the title of leader while working under Japan’s thumb during their occupation of China. He aimed to validate his regime, yet support never materialized. Viewed as a collaborator, not a patriot, he died in 1944 with his legacy steeped in national resentment.

Unknown authorUnknown author on Wikimedia

8. George Blake

From within British intelligence, George Blake quietly delivered thousands of classified files to the Soviets. He even served time for it until a daring prison escape in 1966 changed everything. Fleeing to Moscow, he lived out his days in plain sight, while Britain never stopped calling him a traitor.

Unknown authorUnknown author on Wikimedia

9. Philippe Pétain

Philippe Pétain once inspired France with courage, then led it into disgrace as head of Vichy. His regime enforced Nazi policies and cracked down on resistance, and a treason conviction followed. The French still argue over him, and his legacy remains deeply controversial.

Wabbuh on Wikimedia

10. Edward Snowden

In 2013, headlines exploded when Edward Snowden leaked top-secret surveillance files to the press. The U.S. government charged him with espionage, while privacy advocates called him a hero. Now living in Russia under asylum, he remains a flashpoint in debates over freedom and government transperency. 

https://www.youtube.com/user/TheWikiLeaksChannel on Wikimedia

11. William Joyce

From behind a Nazi microphone, a clipped British accent poured into homes during World War II. That voice belonged to William Joyce, who broadcast propaganda designed to erode morale. Captured after the war, he faced trial and execution, sealing his place as Britain’s infamous broadcaster.

Hardy, Bert, No 5 Army Film & Photographic Unit on Wikimedia

12. Aldrich Ames

Aldrich Ames betrayed the CIA by selling secrets to the Soviets for cash, which led to dozens of agents being compromised, devastating U.S. intelligence. Captured in 1994, he received a life sentence. His actions also exposed shocking internal failures.

staff, Federal Bureau of Investigation on Wikimedia

13. Guy Fawkes

Guy Fawkes wasn’t just a conspirator—he aimed to detonate Parliament and restore Catholic rule, but he got caught before lighting the fuse, and his execution followed quickly. Centuries later, bonfires and masks keep his name alive as a symbol of rebellion and conspiracy.

George Cruikshank on Wikimedia

14. Christopher Boyce

Working in a U.S. defense firm, Christopher Boyce began feeding secrets to the Soviet Union, due to his growing discontent with American foreign policy. Arrested and handed a 40-year sentence, he later became the real-life subject of The Falcon and the Snowman.

The Second Life Of A CIA Double Agent by Journeyman Pictures15. Kim Philby

Kim Philby spent years inside British intelligence while serving Moscow’s interests. As a key figure in the Cambridge Five, he moved secrets under everyone’s noses. When suspicion closed in, he vanished to the USSR in 1963, leaving exposed networks in his wake.

Unknown authorUnknown author on Wikimedia

16. Alger Hiss

His case fueled anti-Communist hysteria in the U.S. Alger Hiss held high-ranking roles in the U.S. State Department while whispers of espionage swirled around him. A perjury conviction came in 1950, but questions over Soviet ties still linger.

Unknown authorUnknown author or not provided on Wikimedia

17. Fritz Joubert Duquesne

Behind enemy lines in both world wars, Fritz Joubert Duquesne orchestrated espionage campaigns against the U.S. and Britain. Nicknamed the “Black Panther” for his stealth, he plotted sabotage with precision, and his arrest didn’t dull the legend.

Jbarta on Wikimedia

18. Klaus Barbie

Fear spread quickly wherever Klaus Barbie operated during World War II. Dubbed the “Butcher of Lyon,” he tortured and killed with impunity. After the war, he aided U.S. intelligence before facing justice. His conviction for crimes against humanity came decades after his victims’ screams.

Unknown photographer (for the NSDAP) on Wikimedia

19. Lavrentiy Beria

Inside the Soviet regime, Beria wielded terrifying power as Stalin’s security chief. He oversaw mass arrests and executions, then made his own move for control after Stalin died. In 1953, fellow leaders turned on him for betrayal and abuse of power, ending his life.

Unknown, presumed official on Wikimedia

20. Andrei Vlasov

Captured during World War II, Andrei Vlasov shocked the Soviet Union by joining Nazi forces. He even organized the Russian Liberation Army to fight against his homeland. His decision branded him a traitor, and when the war ended, the Soviets executed him without mercy in 1946.

Unknown authorUnknown author on Wikimedia