William Stubbs
The growth of the English constitution, author William Stubbs argues, is the result of three forces with reciprocal influences that are constant, subtle, and intricate. These are the national character, the external history, and the institutions of the people. Volume I in his monumental study traces the development of the English government from its Germanic origins in the fifth century to the creation of a state in 1215.
The Constitutional History of England, Volume 1 (Barnes & Noble Digital Library)