Who was the first female Prime Minister of the United Kingdom?

The first female Prime Minister of the United Kingdom was Margaret Thatcher, who served from 1979 to 1990. She was a prominent figure in British politics and a member of the Conservative Party. Thatcher's tenure marked a significant turning point in the UK's economic policies and political landscape, as she implemented a series of reforms aimed at reducing the role of the state in the economy, promoting individualism, and fostering free-market principles. Known as the "Iron Lady," she was recognized for her strong leadership style and her position on various domestic and international issues, earning both admiration and criticism.

The individuals mentioned in the other choices, such as Angela Merkel, Theresa May, and Julia Gillard, were influential leaders in their respective countries—Germany and Australia—but they did not serve as the UK's first female Prime Minister.