Albert Venn Dicey, was a British Whig jurist and constitutional theorist. He is most widely known as the author of Introduction to the Study of the Law of the Constitution (1885). The principles it expounds are considered part of the uncodified British constitution. He became Vinerian Professor of English Law at Oxford, one of the first Professors of Law at the LSE Law School, and a leading constitutional scholar of his day. Dicey popularised the phrase "rule of law", although its use goes back to the 17th century.

Constitutional law is a body of law which defines the role, powers, and structure of different entities within a state, namely, the executive, the parliament or legislature, and the judiciary; as well as the basic rights of citizens and, in federal countries such as the United States and Canada, the relationship between the central government and state, provincial, or territorial governments.