The Queen's remarkable 65 years so far as head of state

In 2015 she became the longest ever reigning British monarch, when her tenure on the throne surpassed that of Queen Victoria. Last year she became the world’s longest running current monarch.

Yesterday, Queen Elizabeth II marked 65 years to the day as head of state. She became queen at the age of 25 in February 1952 on the death of her father, King George VI.

Now Her Majesty is aged 90, and still a remarkably youthful leader. In her recent Christmas message, she had the presence and alertness and appearance of someone in their 70s.

It is no exaggeration to say that the Queen is one of the most important figures in modern British history, even if we look back hundreds of years.

She has presided over a period in which the monarch has no political power (that has been the case for more than a century) yet has to be rigidly impartial. Any breach of that principle would alienate groups of her subjects.

The Queen has managed to do this and not even to say a word out of place during 65 years, with hundreds of meetings and engagements in each of those years.

Like the Duke of Edinburgh, who is aged 95, the Queen keeps a busy diary despite being decades older than the average retirement age.

The dependability of the Queen, in terms of temperament and sense of duty, has made her monarchy a hugely reassuring focal point for the nation over a period of tumultuous change – she was in her teens when World War Two began and an adult when it ended.

The Queen is also been held in high esteem across the countries of the former British empire, which is no mean feat given the speed with which the one-time colonies broke up.

The continuity that the Queen represents is particularly important now, given the political upheaval and uncertainty even in western democracies in recent years.