The Queen turned 89 last month, meaning that she is now in her 90th year.
As we report today, preparations are under way for the next milestone, her 90th birthday next year.
It will rightly be a major event, not that the Queen herself would ever want to make a fuss.
The theatrical spectacular at Windsor Castle next May will, among other things, feature 550 horses, which is apt given the Queen’s love of all things equestrian.
It is extraordinary to reflect on the service of Queen Elizabeth II and the Duke of Edinburgh, who turns 94 next month.
Many people across Britain justifiably choose to retire at the age of 60, if they can afford to do so, after decades in the work place. Yet the Queen and Prince Philip continue to fulfil a busy schedule of engagements three decades past that age.
It is a display of service that explains their deep popularity across the nation. That very popularity has helped to secure the monarchy in one of the few countries in the world that still has a hereditary head of state.
In 2011, when the Queen and Duke won hearts across the Republic of Ireland, they were already both in their late 80s. No-one would have blamed them if they had felt that such a visit had been too much for them. But they pressed ahead with an epochal moment in the history of this island.
The royals immediately in line to the throne are also popular. Next week Prince Charles, a very different figure to his parents but also much loved, will with the Duchess of Cornwall visit both Irish jurisdictions in a single visit. That such a visit is possible, including to the site of the murder of his great-uncle Lord Mountbatten, is a sign of changed times.
This week Prince Harry was winning hearts in New Zealand. This month the world was delighted to see the first daughter of the Duke and Duchess of Cambridge.
These are golden times for the monarchy, thanks to the good character of the royal family’s key members.