Queen Elizabeth, who rallied support for the monarchy despite presiding over what was once known as the world's most famous dysfunctional family, next month becomes Britain's longest-reigning monarch.
She never expected to take the throne and only did so because her uncle abdicated, but on Sept. 9 she will beat the record held by her great-great-grandmother, Queen Victoria, who reigned for more than 63 years.
In this file picture taken on June 2, 1953 Britain's Queen Elizabeth II poses on her Coronation day in London. (AFP)
"It is a job for life," the 89-year-old Elizabeth once said, and unlike some European monarchs recently, and even a pope, she is not expected to abdicate.
While the world and British society have changed dramatically during her reign, the queen has always appeared dependable and reassuring. Despite traumas in the 1990s, such as the death of Princess Diana, that seemed to threaten the monarchy's very existence, the queen has been able to lead the thousand-year-old institution into a new era of popularity.
The diamond diadem, made of diamonds, pearls, silver and gold, worn by Britain's Queen Elizabeth II on her way from Buckingham Palace to Westminster Abbey for her 1953 Coronation and during the first part of the ceremony, is displayed at the exhibition " The Queen's Coronation 1953 " at Buckingham Palace in central London. (AP)
"The key to the change has been anticipating what's coming next," Simon Lewis, her former communications secretary, told Reuters. "The lesson of these last 20, 30 years has been for the institution always to be slightly ahead perhaps of where the British people are."
In this file picture taken on June 2, 1953 The then Archbishop of Canterbury Geoffrey Fisher presents Britain's Queen Elizabeth II with a sword, prior to the Coronation ceremony in London. (AFP)
Britain itself has become a more egalitarian society as old class divides were broken down and deference based on background ebbed away, something reflected in the monarchy itself.
"It's become much less elitist," said royal biographer Robert Lacey. "The monarchy has continued the process of disassociating itself from the social pyramid headed by an aristocracy and attempting to make itself classless."
The Coronation Robe of Britain's Queen Elizabeth is seen during a media preview of the exhibition "The Queen's Coronation 1953" at Buckingham Palace in central London. (REUTERS)
At the start of her reign she was a glamorous figure who seemed to typify Britain's post-war resurgence, but by the 40th anniversary of her accession the royal family appeared to have become little more than celebrity fodder for the tabloids.
While her marriage to Philip, a Greek prince, has stayed solid, she described 1992 as an "annus horribilis" when three of her four children's relationships broke up, with scandalous details exhaustively reported in the papers.
Diana's death in a Paris car crash in 1997 was undoubtedly the darkest moment of her long reign, with the queen forced to return from Scotland to address the nation amid a general outpouring of grief and dismay.
In this file picture taken on June 2, 1953 Britain's Queen Elizabeth II and by Prince Philip, The Duke of Edinburgh wave to the crowds from the balcony at Buckingham Palace following the Coronation ceremony in London. (AFP)
"For about a week it seemed as though the institution had been rocked to its foundation," said Lewis.
With a more professional and sophisticated media operation, the royal family's reputation has been restored from the dark days of the 1990s and even taken to new heights.
Commentators say that also reflects how the queen has provided stability in a time of great social upheaval and growing discontent with elected leaders, while giving Britons a sense of identity.
Britain's Queen Elizabeth II's 1953 Coronation Dress and Robe are seen at the exhibition " The Queen's Coronation 1953" at Buckingham Palace in central London. (AP)
"The fortunes of the monarchy have gone through peaks and troughs, she hasn't really changed but the public reaction to her has," said Professor Philip Murphy, a historian and author of "Monarchy and the End of Empire".
"It's become a significant part of the way we see ourselves as a nation."
Quirk of history
Elizabeth only became queen due to a quirk of history after her uncle Edward VIII abdicated because of his love for American divorcee Wallis Simpson and the crown passed to her father George VI when she was 10 years old.
She was just 25 when she became Queen Elizabeth II on Feb. 6, 1952 on the death of her father. At the time she was on tour in Kenya with her husband Prince Philip, who has been by her side throughout her reign.
"In a way I didn't have an apprenticeship. My father died much too young and so it was all a very sudden kind of taking on and making the best job you can," she said 40 years later.
She was crowned queen of Britain and other realms, including Australia and Canada, on June 2, 1953, in a televised ceremony in Westminster Abbey.
She became the 40th monarch in a royal line that goes back to William the Conqueror, who took the throne in 1066 after winning the Battle of Hastings.
While on the throne, she has seen 12 prime ministers, beginning with Winston Churchill, and bade farewell to the British Empire amassed by her forebears from Kenya to Hong Kong.
Her views on the subject remain a mystery as during her long reign she has never given an interview, and insights into her opinions and character come from brief appearances in TV programmes and from comments by other members of her family.
The most revealing insight into her private life, a documentary titled 'Royal Family' broadcast in 1969 after cameras had followed the queen for a year, has never been shown since, reputedly because it made them seem too ordinary.
"It is a most remarkable achievement to have been in the spotlight for so long and for no one really to have a very strong sense of what her views are," said Professor Murphy.
Although she is the world's oldest living monarch, Elizabeth is only the second-longest currently reigning, behind Thailand's King Bhumibol Adulyadej, who is almost six years ahead of her.
The longest-reigning monarch of all time - King Sobhuza II of Swaziland - ruled for almost 83 years until his death in 1982, while King Louis XIV of France ruled for 72 years, the longest period for any major European country.
During her reign, she has made more than 250 overseas visits to well over 100 countries and met 4 million people in person.
"She ... has surely travelled more widely than any other head of state in history," Prime Minister Cameron told parliament in 2012. "As she herself has been heard to say ... 'I have to be seen to be believed'."
In recent years, she has curtailed her timetable of foreign trips with Prince Charles and other royals taking her place.
While other European monarchs have abdicated, there is no prospect of Elizabeth following suit.
Millions turned out for spectacular celebrations to mark her 60th year on the throne in 2012, while a few months later her starring role in a spoof James Bond film became one of the highlights of the London Olympic Games' opening ceremony.
However, in keeping with her more usual discreet style, aides say she wants little fuss over next month's milestone.
"The fact that my mama has been a constant feature on the scene has provided that sense, I think, of continuity in a time of immense change," Prince Charles said in a documentary to mark her diamond jubilee.
"I suppose when you first set out you don't think about how long things might go on for, but the queen has provided an amazing record of devotion, dedication and commitment."