If Magna Carta and all copies were destroyed would Britain return to the tyranny of the kings or would it have no impact?

 (Asked on Quora - my answer).

No. Britain would not return to the tyranny of the kings. In fact I doubt whether there will be any change to the status quo. For one there has been substantial development in both political and social reform since the signing of the Magna Carta in 1215. These not only include the Reform Acts of 1832, 1867 and 1884 but also the Case of Proclamations (1610) which argued that ‘the King hath no prerogative, but that which the law of the land allows him."

On top of that one could add Dr. Bonham’s Case (the precursor to judicial review in the US), the Petition of Rights (1628), the Habeas Corpus Act of 1679, the Bill of Rights of 1689 and the Claim of Civil Rights Act of the same year

In addition one has several centuries of English common law to fall back to for precedent as well as other Democratic initiatives such as the Slave Trade Act of 1807, the Roman Catholic Relief Act of 1829 and the Parliament (Qualification of Women) Act 1918.

While it is true that the Magna Carta was a profoundly influential document in its original context, political theory has developed significantly since the 13th century especially with respect to natural rights and contract law for which are greatly indebted to such profound thinkers as Edward Coke and John Locke.