At St Margaret's Church in Westminster yesterday, the running joke involved a gag about which family - the bride's or the groom's - ought to be sitting on the right.
The wedding of Orlando Fraser and Clemmie Hambro was, to put it mildly, an occasion that turned the political kaleidoscope on its head. It united two of Britain's grandest, but most diametrically opposed, political dynasties.
Orlando, 39, the son of the historian Lady Antonia Fraser, comes from a line of left-wing icons. His grandfather was the late reformer Lord Longford, and his step-father is that most truculent of champagne socialists: Harold Pinter.
The bride, for her part, boasted the truest of blue Tory roots: Sir Winston Churchill was her great-grandfather. Richard Hambro, her father, is from the banking family, and her mother, Charlotte, is now married to Earl Peel, a land-owning descendent of Sir Robert Peel, one of the most influential Tory PM's of the Victorian era.
On paper, the Hambro and Fraser clans ought to mix about as well as two up-market brands of oil and water. The sight of 600 society guests eyeballing each other during the service and subsequent reception at Claridge's prompted one of their number to declare the event "a political genealogist's wet dream".
The groom was more tactful. "My mother's family is very left-wing and Clemmie's is very conservative," was how he explained things. "It would be safe to say that our wedding will bring all sorts of different people together."
He wasn't joking. Onlookers outside St Margaret's, otherwise known as the Speaker's Church, at 3.30pm yesterday witnessed a virtual "Who's Who" of Westminster's chattering classes trotting through crowds of tourists to the entrance.
David Cameron was there, resplendent in his trademark lime-green tie (Samantha wore leopard-skin). So too was the Tory MP Nicholas Soames on the arm of his mother, Mary, the widow of the former cabinet minister, Lord Soames. No fewer than three dukes - Marlborough, Roxborough and Devonshire - were also in attendance, along with a dozen peers and MPs from both sides of the House.
"St Margaret's is the parish church of the House of Commons," a cathedral spokesman said. "Most couples who want to marry here have to be able to prove that they have family ties to Parliament. It's safe to say that in this case, there weren't too many problems."
The happy occasion was eerily reminiscent of the November day, exactly 75 years ago, when Orlando Fraser's grandfather arrived at St Margaret's to marry Elizabeth Harman, the daughter of a London doctor related to the Chamberlain political family and a noted "bright young thing" of the 1920s.
According to family legend, the future Lord Longford, an occasionally slapdash man, arrived at the altar only seconds before his bride, having originally gone to the wrong church. Despite the hitch, the couple were married for more than 70 years, and produced eight children, 26 grandchildren, and 17 great-grandchildren.
Yesterday's proceedings were also marked by a degree of eyebrow-raising. Clemmie Hambro, who chose her dress shortly after the engagement was announced in July, was forced to have it altered on account of the fact that she was now more than five months pregnant. Her bump was concealed beneath a light-green sash.
One wonders what Sir Winston Churchill would have made of it all. The wartime PM was, after all, like chalk to the cheese of Hambro's new family, which includes a total of 60 Longford descendants, many of them talented authors or left-leaning political figures, in their own right.
Lord Longford - born Frank Packenham - was one of the most influential literary and political figures of the late 20th century. He wrote more than 20 books, and campaigned tirelessly on a host of high-profile penal reform and morality issues.
His CV lays bare a remarkable career. Among other things, Lord Longford was the assistant to Sir William (later Lord) Beveridge at the peak of his career, the First Lord of the Admiralty, the Secretary of State for the Colonies and the Leader of the House of Lords.
Lord Longford was also an outspoken peer who sat on the Labour front bench for a record 22 years, and campaigned tirelessly on behalf of the dispossessed, however unpopular their cause might be.
His best known moral crusades were on behalf of the moors murderer Myra Hindley - one of many convicted prisoners whom he visited - and a battle during the 1970s against pornography and the sex trade. He continued to campaign until his death in 2001, aged 95.
Lady Longford, for her part, wrote 22 historical biographies and died a year after her husband. She had been part of a social set that included Evelyn Waugh and John Betjeman, and was happily married for more than 70 years.
The couple's children include the author and human rights campaigner Lady Rachel Billington, the author of 16 novels and seven children's books.
Orlando is a product of Lady Antonia's first marriage to the late Tory MP, Sir Hugh Fraser. That marriage ended in scandalous circumstances after Lady Antonia left him for the playwright Harold Pinter in the 1970s.
Although Orlando is close to his mother and step-father, his personal politics are thought to be inherited from Sir Hugh, a Second World War hero whom Orlando is said to have idolised.
Orlando, who was educated at Ampleforth and Cambridge and works as a civil barrister at Four Stone Buildings, fought the key marginal seat of North Devon for Michael Howard's Conservatives at the last general election. During that campaign he achieved something of a first in persuading Pinter to attend a Tory fund raiser.
It wasn't all fun and games, though. The campaign became enveloped in controversy after an American journalist reported that he'd referred to women in his prospective constituency as "notoriously hideous".
Although Orlando denied the charge, and posed in Country Life magazine with his pet terrier, Trevor, in an effort to repair the damage, he took a beating at the polls, and was left, according to one relative, feeling "rather bruised". "I don't think Orlando plans to stand for parliament again," the relative said. "In the days of rotten boroughs, he's the sort of former public-schoolboy who would have walked into a safe seat. He was genuinely surprised and hurt when that didn't happen."
His bride, of course, comes from an equally influential clan. She is named after Sir Winston Churchhill's wife, Clementine, and descended from his daughter, Mary (the sister of Randolph).
Clemmie's mother, Charlotte, married her father, Rick Hambro, a popular scion of the banking family. The couple later divorced and, after a brief dalliance with Bryan Ferry, Charlotte married Earl Peel.
As an only child, Clemmie is the heir to a considerable - some say "eye-watering" - fortune. She can also boast several influential MPs, journalists and aristocrats as cousins, and earns a living as a freelance travel writer. "Clemmie's great mentor is the Tatler journalist Victoria Mather, who loves to help out bright young things from posh families," says an acquaintance. "She also had a stint as an actress, and spent some time in New York."
That trip ended in disaster after Clemmie became engaged to the improbably-named American financier Bartle Bull the Third. A few weeks before their wedding, guests were sent postcards informing them that the big day had been cancelled, following a falling out over the pre-nuptial agreement.
Not long afterwards, Hambro's relationship with Orlando Fraser (a long-standing friend whom she had known for almost a decade) hit the gossip columns, to the amazement of pundits who had pegged Fraser as a "confirmed bachelor".
Others weren't surprised though. "In fact, Orlando has always been a ladies man, and has had plenty of girlfriends over the years," one relation said. Another long-standing acquaintance, himself openly homosexual, added: "He's got a slightly effete manner, but despite the dog, he's not well enough groomed to be gay."
Either way, yesterday's no-expense-spared bash, which involved 18 bridesmaids, also recalled Clemmie's first brush with fame when, at the age of five, she was a bridesmaid at Prince Charles' wedding to Princess Diana in 1981.
The event also attracted a smattering of papparazzi, drawn by the prospect of snapping a host of celebrities and well-appointed socialites, including Vogue editor Alexandra Shulman, television presenter Kirstie Allsopp, and Lady Emily Compton, a gossip-column staple who has also been squired by Bryan Ferry.
Whatever their political persuasion, as they eyed the hungry cameramen, the guests may have been driven to reflect that these sorts of events suggest that politics really is the new showbusiness.
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