Sometimes when politics screams and tears its hair out – history can rush forward with a comfort blanket to wrap round its shoulders.
It’s all right it says – calm down – we have been here before.
Britain has left Europe in a huff and been drawn back in again.
It has turned its back on Europe and turned it back again almost as often.
Today is just one of those times.
The ancient province of Britannia was firmly part of the Roman empire for four centuries before that empire’s disintegration forced it to leave in 410.
Two centuries later in 664 England voted at the Synod of Whitby to rejoin what was emphatically a European union – that of the Roman Catholic church – albeit with many a squabble under the likes of Henry II and King John.
In 1534 Henry VIII spectacularly withdrew from that union and Reformation England held itself aloof from Europe’s wars of religion throughout the 16th and 17th centuries.
Then in 1704 England changed its mind and the Whigs plunged into the war of the Spanish succession against Louis XIV.
The Tories reverted to detachment after Utrecht in 1713 and the Hanoverians left Europe well alone.
In 1734 Walpole could boast to Queen Caroline that ‘50,000 men are slain in Europe this year and not one an Englishman’.
The Pitts would subsidise selected European allies but refused to fight with them until Britain was drawn into the war against Napoleon.
It then triumphed at Trafalgar and Waterloo and a London square and a station were erected as memorials to the cause of a newly united Europe.
At the Congress of Vienna in 1815 Britain helped found the Concert of Europe – to resolve the continent’s future conflicts peacefully.
But it soon lost interest – to concentrate on trade with our old friend ‘the rest of the world’ – or rather the empire.
It re-engaged for the Crimean war but disengaged to leave Bismarck his supremacy.
Lord Salisbury declared a European policy to be one of ‘splendid isolation … drifting lazily downstream – occasionally putting out a boat-hook to avoid collision’.
In the 20th century isolation met its nemesis: Britain was drawn into a great war it should have helped avoid.
It then appeased France’s desire for revenge against Germany and appeased its inevitable outcome – the rise of Hitler.
When Baldwin in 1934 promised ‘freedom from adventures and commitments abroad and no rearmament’ – it was the climax of the age of leave.
The outcome was a second world war.