Step 1: Define the "Rule of Law".
The Rule of Law is a fundamental principle of governance. It essentially means that no one is above the law, including the government itself. It implies the supremacy of law, equality before the law, and the predominance of a legal spirit.
Step 2: Trace its modern constitutional origin.
While the concept is ancient, its modern formulation in constitutional law is most strongly associated with the legal system of the United Kingdom (UK).
Step 3: Identify the key proponent.
The British jurist and constitutional theorist A.V. Dicey is credited with popularizing and elaborating the concept of the Rule of Law in the late 19th century. His work was highly influential, and because of this, the doctrine is considered a core part of the UK's uncodified constitution and a major feature borrowed by India.