Margaret Thatcher was the first female prime minister of the United Kingdom. She established an intellectual corpus focusing on three primary principles. First, the state must concentrate its forces on sovereign domains. Second, the sovereignty of the United Kingdom is paramount. Third, a triptych of Anti-communism, defence of Atlanticism and resolute Euroscepticism. Pursuing such aims, she passionately pursued privatisation and attacked trade union power and workers' rights. This chapter will evaluate her domestic political leadership.