No historical figures are more reviled than traitors. Many of their betrayals have had a significant impact on history and the fate of nations. Such is the depth of their treachery that many of their names -Vidkun Quisling, Benedict Arnold, Mir Jafar, and Judas Iscariot – are synonymous with disloyalty.

To determine the most famous traitors in history, 24/7 Tempo consulted sources including Britannica, Biography, and History, as well as various news sites.

The first question asked about traitors is why would someone betray one’s own country? The motivations are many, but the most common is money. Andrew Daulton Lee, a drug dealer from California, passed on secrets to the Soviet Union in the 1970s for cash. An expanding bank account of long-time turncoat CIA agent Aldrich Ames piqued the interest of American intelligence services. When FBI agent Robert Hanssen was arrested for espionage, he said his only motivation was financial. (These are the most famous spies in history.)

Ideological reasons are another incentive for people to turn on their country. In the 1930s, Cambridge University students were recruited by the Soviet Union to spy on Great Britain. The so-called  Cambridge Five were convinced that Marxism was the best counterweight to the rise of fascism and passed intelligence to Soviet Russia. In our own era, John Walker Lindh, from California, converted to Islam and wound up fighting for the Islamic extremist group the Taliban against the U.S. and its allies in 2001. 

For others, simple opportunism was the rationale for betrayal. Ephialtes showed the Persian army of Xerxes a way around the Spartan force at Thermopylae, hoping for an influential place in a Greece conquered by Persia. That was also the motivation for Pierre Laval, the French politician who collaborated with Nazi Germany, which he was convinced would win World War II. (The Nazis were defeated in part due to their loss in some of the biggest battles of WW II.) 

Some of the traitors on the list had distinguished themselves in battle, such as Benedict Arnold, Andrey Vlasov, and Philippe Pétain, only to desert their country. 

Click here to see the most famous traitors in history

Nearly half of the traitors on this list met a grim end, whether by execution, accident, or suicide. One who died by her own hand was Stella Kubler, one of the more reprehensible people in history. Kubler, born into a Jewish family in Germany, was a “Jew catcher” – a Jew working for the Nazis to find other Jews in hiding. Kubler outed her co-religionists, many of them ex-schoolmates and even some relatives, for money.