Margaret Thatcher was known as the "Iron Lady" during her time as Prime Minister of the United Kingdom, serving from 1979 to 1990. This moniker reflected her strong and uncompromising leadership style, especially during the Cold War period when she was a vocal critic of the Soviet Union. Thatcher was the first female Prime Minister in the UK and was renowned for her economic policies promoting deregulation, privatization, and reductions in public spending, often referred to as "Thatcherism." Her tenure reshaped British politics and economics, leaving a lasting legacy that continues to influence the Conservative Party today.