Most Britons still lived and died without encountering anyone whose skin colour was different from their own. Slaves, in short, did not threaten, at least as far as the British at home were concerned. Bestowing freedom upon them seemed therefore purely an act of humanity and will, an achievement that would be to Great Britain's economic detriment, perhaps, but would have few other domestic consequences.

In the last quarter of the 20th century, Britons have been understandably obsessed with the problem of having too little power in the world. In the third quarter of the 18th century, by contrast, their forebears were perplexed by the problem of having acquired too much power too quickly over too many people.

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.

Recognising that an ostentatious cult of heroism and state service served an important propaganda function for the British elite does not mean, of course, that we should dismiss it as artificial or insincere. All aristocracies have a strong military tradition, and for many British patricians the protracted warfare of the period was a godsend. It gave them a job, and, more important, a purpose, an opportunity to carry out what they had been trained to do since childhood: ride horses, fire guns, exercise their undoubted physical courage and tell other people what to do.

It would be wrong to interpret the growth of British national consciousness in this period in terms of a new cultural and political uniformity being resolutely imposed on the peripheries of the island by its centre. For many poorer and less literate Britons, Scotland, Wales and England remained more potent rallying calls than Great Britain, except in times of danger from abroad. And even among the politically educated, it was common to think in terms of dual nationalities, not a single national identity.

A British imperium enabled Scots to feel themselves peers of the Ebglish in a way still denied them in an island kingdom. The language bears that out very clearly. The English and the foreign are still all too inclined to refer to the island of Great Britain as 'England'. But at no time have they ever customarily referred to an English empire.

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.