George Blake, a British MI6 agent, became one of the most notorious double agents in history when he defected to the Soviet Union in 1961. Born in the Netherlands to British parents, Blake joined MI6 in 1944 and quickly rose through the ranks. During the Cold War, he was stationed in various countries, including Poland, Germany, and South Korea. In 1951, while working in Seoul, Blake was captured by North Korean forces during the Korean War. During his captivity, he was interrogated and tortured, and he eventually agreed to work for the Soviets. After his release in 1953, Blake returned to England and continued to work for MI6, all the while passing valuable secrets to the Soviets. In 1961, he was unmasked as a double agent and was sentenced to 42 years in prison. However, in 1966, Blake managed to escape from prison and flee to the Soviet Union, where he lived until his death in 2020.