Introductions were not necessary, though perhaps a judicious seating plan was, as the Queen paid a rare visit to Downing Street for a lunchtime gathering of all but one of her surviving prime ministers.
The red carpet was rolled out in front of No 10's famous black door for an intimate lunch hosted by its present tenant David Cameron, and his wife Samantha, to celebrate the 86-year-old monarch's diamond jubilee. The Queen and Duke of Edinburgh were joined by four of the twelve prime ministers to have served during her 60-year-reign.
Given the hours Her Majesty has spent face-to-face with each during their weekly audiences, there would have been a relaxed air of familiarity at the private gathering. Nevertheless, with a guest list including Tony Blair and Gordon Brown – as well as Sir John Major – some delicate diplomacy may have been required.
A running joke at Westminster was that invitees Sir Jeremy Heywood, the cabinet secretary, and deputy prime minister Nick Clegg would be expediently placed at the table, perhaps between the two former Labour PMs. "Everyone likes Jeremy. He's worked with almost every prime minister. He is the ultimate survivor", joked one source.
As the Queen posed for official photographs – with Cameron and Major to her right, and Blair and Brown to her left – there was nothing in the broad smiles to belie any political rancour. Blair had arrived several minutes ahead of Brown, leading to speculation they had been given different arrival times to avoid meeting in front of the Downing Street cameras.
Blair was without his wife, Cherie, who was abroad on business. Brown was accompanied by his wife, Sarah. Major attended with his wife Norma, for whom a visit to No 10 probably evoked the least nostalgia. She reportedly disliked the place, preferring to stay in the family home in her husband's Huntingdon constituency during his tenure.
Absent was Lady Thatcher, to date the Queen's only female prime minister, who has retired from public life and was believed to be too frail to attend.
It is not often the sovereign sets foot inside No 10. Indeed, Cameron is believed to be only the sixth PM to extend such a social invitation to the Queen. In 2002 Blair threw a lavish black-tie dinner to mark the golden jubilee attended by Sir Edward Heath, Lord Callaghan, Thatcher and Major, as well as relatives of five late prime ministers.
According to Alastair Campbell's recent diaries not everyone was upbeat. "Ted Heath, complaining about the seating plan" he noted. "Thatcher was complaining loudly about the decor and the paintings, how some of the carpets and furnishings looked worn, and the colours in the Green Room weren't properly co-ordinated, tut-tutting, not exactly saying 'wouldn't have happened in my day' but not far off," recalled Campbell.
Heath, apparently, "could barely bring himself to look at Thatcher, but she teased him a bit, tried to make him laugh, without any apparent success," added Campbell.
In keeping with Cameron's 'austerity for all' message, this was a scaled-down version of Blair's bash with a guest list of just 12 – including Clegg, his wife Miriam González Durántez and Heywood – and a menu of salmon, roast duck with potatoes and seasonal vegetables, and trifle.
Because of the longevity of the Queen's reign, and the young age at which she acceded the throne, she has unsurprisingly long-outlived her earliest prime ministers.
Her first, Winston Churchill, who was much taken with the 25-year-old sovereign and nurtured her through her early years, extended the first dinner invitation to Downing Street on the occasion of his retirement in 1955. Equally charmed was Harold Wilson, who invited her at the time of his resignation in 1976.
Much has been rumoured about the relationship the Queen is said to have shared with Thatcher, with suggestions the monarch found the latter "a bit of a frost". But that did not appear to be evident when Thatcher invited the Queen to dinner in December 1985 to celebrate the 250th anniversary of Downing Street as the official residence of the prime minister.
John Major threw a similar dinner to celebrate the 80th birthday of Sir Edward Heath in 1996. Four years previously he had organised another dinner for former prime ministers at Spencer House in St James's Square, which the Queen attended.
It is not the first time Cameron has welcomed the Queen to No 10. The red carpet was rolled out for her and the Duke of Edinburgh last year, in honour of Prince Philip's 90th birthday.
