Margaret Thatcher was the longest-serving Prime Minister of the twentieth century, the first female leader of a major political party and the first female Prime Minister. These simple facts would in themselves have guaranteed her an elevated place in the pantheon of British political history. However, further claims can and have been advanced about her. For instance, that she presided over a sea change in the governance of the British economy in that she rejected the nostrums of the Keynesian post-war consensus and looked instead to the free market economy. In the process Thatcher laid claim to having ended and indeed reversed Britains economic decline, and in so doing to have cured the British disease of disruptive industrial relations by taming the trade union movement. Nor was it simply in the domestic sphere that Thatcher claimed to have had an impact. In foreign relations the label the Iron Lady preceded her Premiership, but her battle over the European budget, Britains victory against Argentina in 1982, her commitment to the Cold War and the fall of the Berlin Wall, all seemed to justify her moniker. This book is not a biography of Margaret Thatcher. It is a study of how her 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 the British political pantheon.