The Anglo-American tradition of “rule of law” is distinct from that of continental Europe or Confucianist traditions in Asia, both of which are primarily concerned in different ways with the health of the state. Anglo-American “rule of law” has been an evolutionary - and sometimes revolutionary - march to constrain the exercise of arbitrary power and, eventually, assure an egalitarian access to justice.
Lord Chief Justice Sir Edward Coke, a great man to whom much is owed, but who today is largely forgotten, was the great theorist and defender of judicial independence and common law from the whims of a sovereign. Without judicial independence, the rule of law is hardly possible because it is ultimately inseparable from the executive power; Coke was instrumental in moving elite Englishmen’s minds from accepting “Rex lex” (”The King is Law”) to demanding “Lex rex” (”The Law is king”).
The matter was not formally settled with the English Civil War, which came not long after Coke’s death, or even the Glorious Revolution of 1688; nor the American Revolution of 1776 or even at Appomattox Courthouse. “The rule of law” is an ongoing struggle that must be constantly renewed by an active and vigilant citizenry if it is to be sustained.