The most notable absentees from the Monarchs' lunch at Windsor were the King and Queen of Spain, whose government interdicted their visit because of the continuing dispute over the sovereigny of Gibralter - the issue which prevented their attending the wedding of the Prince and Princess of Wales in 1981.
This year is proving something of an annus horribilis for the King and Queen, who did not publically celebrate their Golden wedding last Monday. The various rumours of scandal around members of the Royal family as are recorded, in a rather negative way, in this report in the supposedly conservative Daily Telegraph.
In one sense this can be seen as a coming of age for the restored Spanish monarchy - like the other reigning dynasties of Europe they have become fair game for the bored and opinionated, for those with a fine nose for scandal and the grinding of particular axes. Too often, far too often it is the open season for sniping. Misjudgements there may have been, and mistakes made, but monarchs are human - that is one of the strengths of monarchy - it is not a machine.
In the last generation or so we have seen the Swedish monarchy prounced terminally doomed from before the present King's accession in 1973, the hostility to the present Queen of the Netherlands' marriage in the 1960s, the allegations around her father in 1976, and doubts as to the future at the time of her accession in 1980.
Here in the United Kingdom the problems of the mid 1990s were only too publically aired and discussed, and even in Denmark Prince Henrik has been the centre of various storms as indicated here.
In Luxembourg and Lichtenstein the constitional position of the monarch has been under fire and in Belgium the very future of the country, and hence the monarchy, questioned.
For the Spanish monarchy there is the problem of the hiatus between 1931-75, even if the monarchy was formally re-established in 1947. It has been argued that, despite the hitherto enormous popularity of the King, Spain itself is not a sufficently monarchist society. I do not know if that is true, but I can see that there might be some cause for concern for the future there. On the other hand this could be dismissed as the chattering classes at it again - and how they can chatter on such matters.
So it is not easy, and for the moment it is the Spanish crown that is under the public scrutiny. The country has far more serious problems with which to concern itself, and should in no way belittle the extraordinary and fundamental achievements of the King and Queen and the Prince of Asturias in providing the stable constitutional framework that allows it as a nation to try to deal with the consequences of the eurocrisis, and which has guided it since 1975.
Viva El Rey!