Britain is so used to having the Queen and the Duke of Edinburgh at the helm of the state that it is easy to forget the fact that their eldest son is himself well past retirement age.
Prince Charles will reach his 70th year in November.
The heir to the throne’s parents are so active and committed to national duty that they have attended engagements into their 90s at a pace from which some working people begin to wind down in their late 50s.
Last week it was announced that Prince Philip will cease carrying out official engagements in the autumn, when he is 96.
The announcement was met with sadness but widespread understanding, given his great age.
Prince Charles and the Duchess of Cornwall, in the mould of the Queen and her consort, are also staying fully engaged in public commitments.
It is a sign of the extraordinary longevity of the Windsors that Prince Charles’s energy levels are such that it does not seem strange that the most important phase in his life has not yet begun.
The couple are, like all senior royals, regular and seemingly enthusiastic visitors to Northern Ireland. Yesterday they paid tribute to the 13 PSNI officers who have died in the line of duty when the prince opened a memorial to those fallen.
They also visited Dromore in Co Down, the day after they were in Londonderry and at the Seamus Heaney centre in Bellaghy.
Not for the first time, Prince Charles and the duchess crossed the border, something that until recently never happened on the same royal trip.
That was is a welcome symbol of some normality at a time of political turbulence and ongoing, albeit intermittent, terror.
All the way through the Troubles and beyond, these royal visits have been an important source of comfort for the Province and provided a sense of continuity.