Margaret Thatcher the longest-serving Prime Minister of the twentieth century, the first female leader of a major British political party, the first female British Prime Minister. These simple facts alone have guaranteed her an elevated place in the pantheon of British history, but this self-styled Iron Lady made a political impact that is still being felt to this day. Her style of leadership attracted extremes of adoration and loathing that reached far beyond the usual parameters of party division. To supporters, she removed the grey from politics in favour of black and white, while to opponents, she appeared ruthless and seemed indifferent to the social consequences of her economic agenda. This is a study of how her formidable reputation in both the domestic and international sphere was constructed by Thatcher and others over the course of her career. Notably, this is the first scholarly treatment to make full use of the Thatcher Archive, and as a result has comprehensively reassessed and re-evaluated her place in British history.