At one level Great Britain at the beginning of the 18th century was like the Christian doctrine of the Trinity, both three and one, and altogether something of a mystery.

A fundamental reason why Britain was not torn apart by civil war after 1688 was that its inhabitants' aggression was channelled so regularly and so remorsely into war and imperial expansion abroad.

Jacobitism involved much more than a debate about the merits of a particular dynasty. Men and women were well aware that its success was almost certain to involved them in civil war. And the more politically educated knew that the Stuart Pretender was a pawn in a worldwide struggle for commercial and imperial primacy between Britain and France.

In the past, the British had signally failed to build an effective structure of royal authority and administration in their American colonies. As a result, no possibility existed of soothing and winning over influential and talented Americans, in the way that influential and talented Scotsmen were increasingly being won over, by giving them increased access to state employment.

Virtually every war fought since the Act of Union had gone badly at some stage, but before 1783 none had ended in defeat. Nor would any major war in which Britain was involved after this date end in defeat. Those who are curious about this country's peculiar social and political stability probably need look no further than this for essential cause.

An unprecedented number of uniformed males, marching, parading and engaging in mock battles in every region of Great Britain brought a pleasant frisson of excitement into many normally quiet and deeply repetitive female lives.

The pre-war empire had been sufficiently informal and sufficiently cheap for Parliament to claim authority over it without having to concern itself too much about what this authority entailed. The post-war empire necessitated a much greater investment in administrative machinery and military force. This build-up of control had to be paid for, either by British taxpayers or by their colonists.