Margaret Thatcher was known as the "Iron Lady." She earned this nickname due to her strong and unwavering political stance, particularly during her time as Prime Minister of the United Kingdom from 1979 to 1990. Thatcher was known for her conservative policies, commitment to free-market principles, and hardline approach to the Soviet Union during the Cold War. The term also reflects her no-nonsense attitude and determination in politics, earning her both supporters and detractors. Her leadership significantly shaped British politics and policies, leaving a lasting legacy.