Queen Elizabeth and husband Prince Philip mark their platinum wedding anniversary with a small family get-together on Monday, a far cry from the pomp and celebration which greeted their marriage 70 years ago.

The couple married at London's Westminster Abbey on Nov. 20, 1947, just two years after the end of World War Two, in a glittering ceremony which attracted statesmen and royalty from around the world and huge crowds of cheering well-wishers.

Seventy years on, no public events are planned. Elizabeth, now 91, and her 96-year-old husband, who retired from active public life in August, will celebrate the milestone with a private party at Windsor Castle, the monarch's home to the west of London. For her part the Queen is slowly passing over some of her official duties to her son Prince Charles, now aged 69.

This year contrasts with their silver, golden and diamond wedding anniversaries when they attended thanksgiving services at the thousand-year-old Abbey, where the queen was crowned and where her grandson and his wife, William and Kate, were married in 2011.

However, the Abbey itself will mark the occasion with a full peal of its bells involving 5,070 change of sequences, with the 70 reflecting the anniversary, which will last more than three hours.

"Congratulations to The Queen and The Duke of Edinburgh as they celebrate their Platinum Wedding anniversary," Prime Minister Theresa May said on Twitter. "They have devoted their lives to the service of the UK and the Commonwealth - my best wishes to them both on this special occasion."Also in honor of the occasion, Buckingham Palace on Saturday issued new photographic portraits of the Queen and the Prince, taken earlier this month by photographer Matt Holyoak in the White Drawing Room at Windsor Castle.

They are framed by Thomas Gainsborough's 1781 portraits of George III and Queen Charlotte, whose 57-year union -- bridging the 18th and 19th centuries -- is the next longest British royal marriage.

In one of the photographs released, the Queen poses in the same cream dress designed by Angela Kelly she wore at her diamond wedding anniversary thanksgiving service 10 years ago, along with a yellow gold, ruby and diamond "Scarab" brooch Philip gave her in 1966.

Meanwhile the Royal Mail, Britain's postal service, has issued a new set of six stamps to commemorate the historic landmark.

It includes images of the pair's engagement announcement at Buckingham Palace, their wedding amid the splendor of Westminster Abbey, and the first part of their honeymoon at a country estate in the county of Hampshire.This is a June. 2, 1953 file photo of Queen Elizabeth and Prince Philip, Duke of Edinburgh, as they wave to supporters from the balcony at Buckingham Palace, following her coronation at Westminster Abbey. London. (AP Photo)The wedding of Princess Elizabeth, as she then was, to the dashing naval officer Philip Mountbatten was seen as raising the nation's spirits amid an austere background of rationing and shortages that followed the war.

"Millions will welcome this joyous event as a flash of color on the hard road we have to travel," said former Prime Minister Winston Churchill.

Five years later, Elizabeth succeeded her father George VI on the throne and has ruled for the following 65 years, more than any other monarch in British history, with Philip by her side throughout. They become Britain's first reigning couple to mark a platinum wedding anniversary.

"The support he gives to my grandmother is phenomenal," Prince Harry said in a documentary to mark her 60th year on the throne.

"Regardless of whether my grandfather seems to be doing his own thing, sort of wandering off like a fish down the river, the fact that he's there - I personally don't think that she could do it without him."

While the couple's marriage has remained strong, three of their four children -- Charles, Anne, Andrew and Edward -- have seen their unions end in divorce, most notably heir Prince Charles's ill-fated union with his late first wife Princess Diana.

"He has, quite simply, been my strength and stay all these years," Elizabeth said in a speech to mark the couple's 50th wedding anniversary in 1997.

Royal historian Hugo Vickers said the secret of their long marriage was their mutual support and devotion to duty.

"They don't waste a jot of time wondering whether we like them or not - they just get on with the job," he told Reuters.

"On the occasions when I have been lucky enough to see them together, they always look incredibly comfortable in each other's company."In this Saturday, June 17, 2017 file photo, members of Britain's Royal family from left, Camilla, the Duchess of Cornwall, Prince Charles, Princess Eugenie, Queen Elizabeth II, background Timothy Laurence, Princess Beatrice, Prince Philip, Kate, the Duchess of Cambridge, Princess Charlotte, Prince George and Prince William watch a fly past as they appear on the balcony of Buckingham Palace, after attending the annual Trooping the Colour Ceremony in London. (AP Photo)The couple also boast eight grandchildren and five great-grandchildren, with a sixth great-grandchild expected in April, when Prince William and wife Kate Middleton's third child is due.

Queen Elizabeth became the U.K.'s head of state in 1952, aged just 25. She succeeded her father, King George VI, after his death on Feb. 6 that year.

The 91-year-old monarch has become the first British royal to reach a sapphire jubilee after 65 years on the throne.

Queen Elizabeth became the longest-serving monarch of Britain in 2015 at the age of 89 and has seen 14 prime ministers come and go, including Winston Churchill and Margaret Thatcher.

Joseph Stalin was the leader of the USSR and Harry Truman was the president of the U.S. when she ascended to the British throne.

The royal couple first met as teenagers, and eventually married when Elizabeth was a 25-year-old princess.

Philip, the son of a Greek prince banished from that country, renounced his titles and Greek Orthodox faith and became a British citizen in order to marry, adopting his mother's anglicized name, Mountbatten.

Prior to the wedding he told the Queen Mother he had "fallen in love completely and unreservedly" with her daughter.

Since described by Elizabeth as her "rock," Philip once remarked: "My job first, second and last, is never to let the Queen down."