A form of political history, constitutional history was interested in the institutions that shaped the development of the modern nation state (particularly parliament) and in the study of the documents relating to them. It has been associated with a 'Whiggish' approach to history, in that exponents like Trevelyan portrayed constitutional developments as being central to the gradual progress towards a modern liberal and tolerant Britain. Administrative history shifted the focus of study to the individual institutions of the state and subsequent the individuals involved with them, culminating in the in-depth prosopographical work of Namier on the parliaments of George III. Since the 1960s political history has had to adapt to the challenges to its narrow definition of politics and its methodology from social and cultural history, and as a consequence constitutional history in its old form is little practised.