Eight hundred years ago, England's nobles allied against the rapacious King John to restrain his excessive taxation and irresponsible attempts at foreign conquest. The alliance prepared a list of rules that John had to follow to regain their allegiance and maintain his throne. The "Great Charter" was the first significant step in a centuries-long odyssey toward the ideal of limited government. This talk discusses Magna Carta's catalytic role in the history of constitutions and liberty.