This chapter explores the relationship between dress, identities and agency in the public realm, and thus contributes to wider feminist debates about women politicians and the politics of dress and gender. It focuses on how Margaret Thatcher used dress to define her political image, draw from her upbringing to adapt and shape her dress, then analyses the different and shifting performances of dress across her life and career. Much feminist analysis of dress in contemporary British politics argues that media focus on women's dress is always damaging and marginalizing. Dress and its relationship with political culture remains an underdeveloped aspect of political sociology, international relations and history. The micro-politics of dress during the interwar years reflected and provoked broader socio-economic changes in British society. Thatcher's dress reflected and embodied her growing power in both domestic and international terms, and defined a particular form of executive style for women.