When the queen came to the throne in 1952, Winston Churchill was prime minister; and now her prime minister is four years’ younger than her youngest son.
We now have only one current MP first elected in the 1950s (Sir Peter Tapsell) and two people alive who served as MPs before 1952 (John Freeman and Tony Benn). Whilst there are three or so current peers who have sat in the house of lords longer than the queen has reigned (Lord Carrington entered in 1945), there are very few figures in British public life which have had any prominence over the same period.
Perhaps only Dame Vera Lynn has been a national celebrity for a longer time.
Sixty years of public service is something to be celebrated. And the way the queen has done it also should be cheered: her self-control and lack of personal showiness is a model of what a monarch should be like, if we are to have a monarchy at all.
There are somethings to be said for the crown in domestic politics and law.
First, it is less important for the power it has than for the power it prevents others having.
Second, it provides the most general concept of the state we have in (at least) English law – almost all executive, legislative and judicial power is exercised in the name of the crown, one way or another.
And third, it provides a superficial sense of continuity from medieval times (if one ignores that in 1640, 1660, 1688, 1714, and 1936, the fate of the crown was determined by others).
All that said, there is a basic principle: supreme executive power in any modern polity really should be in the hands of someone who is accountable and capable of removal by some formal process.
Nonetheless, switching a “united kingdom” to a republic would be a complex and slow process, and it is one unlikely to be done by any government one can imagine.
The current generation of politicians cannot get round to reforming the house of lords.
Indeed, they cannot even modify a honours system ridden by “knights”, “dames” and the “British Empire”.
So republicanism will remain as a frame of mind, a sense that things could be better organized, rather than as a serious political programme.
And this taming of republicanism is not the least of the queen’s achievements, though one suspects it will not be one of her eldest son’s.