It is almost piquant that a flight to Rwanda has sparked off a debate which raises fundamental questions about the nature of law and government and has deep roots in history. This is an issue which many Conservatives have been happy to evade. That is understandable. It is also wrong.

Historians have not finished with explaining the origins of the English Common Law: what a wonderful name. How did the law of Westminster Hall at the beginning of the 12th century become the law of all England by that century’s end? Could it have been because monarchs were distracted by events in Normandy, or by Crusading (Richard the Lionheart) – or, most obviously, by civil war (Stephen and Matilda)? In those circumstances, lawyers would naturally fill the vacuum. Equally, monarchs would use law as a means of enforcing their authority.