Margaret Thatcher was the first female British Prime Minister, serving from 1979 to 1990. Known as the "Iron Lady," she was a prominent member of the Conservative Party and led a government marked by significant economic and social reforms. Her policies aimed at reducing the role of the state in the economy, promoting free markets, and curbing inflation. Thatcher's tenure saw a strong emphasis on individualism and entrepreneurship, along with a controversial approach to labor unions and public services. Her leadership style and policies left a lasting impact on British politics, setting the stage for modern conservative governance.