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

Margaret Thatcher, from 1979 to 1990 - the longest continuous premiership of the twentieth century, and the most divisive. She remains the only British prime minister to have an adjective made from her name that is used seriously by both admirers and opponents to mean opposite things.

Her background is the part often flattened. She was a grocer's daughter from Grantham who read chemistry at Oxford and worked as a research chemist before law and politics - part of a team working on emulsifiers for ice cream, which produced the durable and probably unfair claim that she helped invent soft-serve. She was also the last British prime minister with a science degree.

The judgement on her record is not going to settle. She broke the power of the trade unions, privatised large parts of the state, and presided over the deindustrialisation of whole regions that have not recovered - so she is remembered as the person who rescued a failing economy or as the person who destroyed communities, depending largely on where the person remembering grew up. She was removed not by an election but by her own party.