Aside from the stately duties of launching ships, hosting garden parties and sitting for portraits, former Diplomatic Editor of The Times Michael Binyon says it is Her Majesty’s engagement with the outside world that underlines the breadth and success of her long reign as Head of State 

No diplomat alive today has ever presented credentials in London to any head of state except the Queen. It is almost 64 years since the last ambassador was received by King George VI. And the Queen, who in September overtook Victoria to become the longest-reigning monarch in British history, has also received, entertained and honoured more diplomats, British and foreign, than any other head of government in the world.

Her workload is still extraordinary – the more so for a woman who will be 90 in a few months time. Almost every week during her reign, she has held an audience with the Prime Minister, beginning with Sir Winston Churchill. David Cameron is her thirteenth – and was himself born after she came to the throne. She has attended every opening of Parliament except in 1959 and 1963, when she was expecting Prince Andrew and Prince Edward respectively. She has given royal assent to more than 3,500 laws passed by Parliament. And she has been served by seven Archbishops of Canterbury.

  She has also launched 21 ships, sat for more than 130 portraits, hosted one and a half million people at her garden parties, owned 31 corgi dogs, appeared on more than 300 different postage stamps around the world, and given out more than 90,000 Christmas puddings to the staff who work for her.

It is her engagement with the outside world, however, that underlines the breadth of her experience as Britain’s head of state. The Queen has undertaken 270 visits overseas, including 113 state and official visits, and has received more than 100 state visitors to Britain as well as hosting tea parties, lunches and other receptions for scores of overseas leaders and prime ministers. She has visited Australia 16 times, Canada 22 times, Jamaica six times and New Zealand 10 times.

Unusual live gifts given to the Queen on foreign tours include two tortoises presented in the Seychelles in 1972; a seven-year-old bull elephant called ‘Jumbo’ given to Her Majesty by the President of Cameroon in 1972 to mark her silver wedding; and two black beavers given after a royal visit to Canada.

Her leadership of the 2.2 billion-strong Commonwealth is one of the most important political commitments of her reign. She is Queen – and therefore head of state – of 15 Commonwealth countries (as well as Britain), including Australia, New Zealand and Canada. As head of the 53-nation organisation, she attends almost every Commonwealth Day reception in London. On her first Commonwealth tour, which began on 24 November 1953, she visited Canada, Bermuda, Jamaica, Panama, Fiji, Tonga, New Zealand, Australia, the Cocos Islands, Ceylon, Aden, Uganda, Libya, Malta and Gibraltar. (Panama and Libya are not Commonwealth members). The total distance covered was 43,618 miles.

She also made a historic visit to the Republic of Ireland in May 2011, the first by a British monarch since Irish independence (King George V had visited in 1911).

  Foreign diplomats are invited to attend a number of functions each year at which the Queen is present, including the state opening of Parliament, some of the garden parties given in summer at Buckingham Palace, receptions, banquets and events such as Royal Ascot, the races where the Queen particularly enjoys herself.

Ambassadors will first find themselves in her company when they present their credentials soon after arriving in London. She takes this role, which dates back hundreds of years, very seriously. It follows an almost unvaried formula. The Ambassador is collected from the embassy or residence by a state landau from the Royal Mews, escorted by the Marshal of the Diplomatic Corps, who is based at St. James’s Palace. The Ambassador’s suite follows in another state landau. During the 20-minute audience, the Ambassador presents letters of credence or letters of commission and his or her suite is presented to the Queen. The Ambassador’s party then returns to the embassy or residence by carriage.

   As with almost all her meetings, the conversation is private and ‘off the record.’ The envoy being presented is expected not to publicise the Queen’s remarks. These are seldom controversial, however: during her long reign she has become an expert at making polite conversation without revealing her own views on politics and without saying anything that might be taken as a comment on the Government’s policies.

  It is, perhaps, a little different when the Queen receives a British Ambassador before he takes up his new post overseas. The Queen may well discuss the country in question and ask the Ambassador his views on the situation there. His title, after all, is ‘Her Britannic Majesty’s Ambassador,’ so in theory he is expected to report directly to her, although in practice all his or her telegrams will be sent back to the Foreign Office and not to Buckingham Palace. The Queen probably will know what to ask: she has vast experience of most countries and during her reign she has visited 116, many of them more than once.

She has also undertaken several visits of religious, rather than political, significance. Ever since the reign of Henry VIII, the King or Queen has been head of the Church of England, the established Church. In practice, she is not expected to make any religious or theological pronouncements. But the role takes on greater importance in Britain’s relations with Rome. The Queen has received two Popes on visits to the UK (Pope John Paul II in 1982 and Pope Benedict XVI in 2010). Pope John Paul II’s visit in 1982 was the first papal visit to the UK for over 450 years. Her Majesty has officially visited the Vatican four times in her reign – in 1961 visiting Pope John XXIII and in 1980 and 2000 visiting Pope John Paul II. Her most recent visit, lasting less than a day, was in April last year when she met Pope Francis.

  Being head of state in a media age, symbolism plays an important part in all that she does. This was clear from her choice of what to do on 9 September, the day when she overtook Victoria’s 23,226 days on the throne. The Queen decided to play down her achievement in beating the record. Instead, she undertook a high-profile visit to Scotland, where relations with the monarchy have been recently strained after the Scottish referendum last year on independence. On the day itself, she visited a 30-mile railway line that has been rebuilt between Edinburgh and Tweedbank, in the Borders country, in the company of Nicola Sturgeon, the Scottish First Minister (and known opponent of the monarchy).

 To mark the event, the Queen rode behind a steam engine. It was a reminder that it was Queen Victoria who saw the beginning of Britain’s railway age. The engine chosen for the visit was a finely preserved steam train, the A4 Union of South Africa – a subtle link to her own visit to South Africa in 1947 when, as Princess Elizabeth, she made a speech on her twenty-first birthday dedicating her life – “whether it be long or short” – to serving the British Empire and Commonwealth. No one then foresaw how long that life would be.