With the royal spotlight firmly fixed on the arrival of Prince William's third baby and Prince Harry's wedding, it would be easy for the Queen to let her latest milestone to slip by quietly.
But the Queen's 92nd birthday will be celebrated in style on Saturday, with a star-studded concert in London and gun salutes ringing out across the city and near her home at Windsor Castle.
While many of her peers are well into retirement, the Queen still carries out a busy schedule of public duties as patron or president of more than 600 charities, military associations, professional bodies and public service organisations.
For several decades her husband the Duke of Edinburgh was by her side for many of them until last August when the 96 year old retired from public life.
"The Queen and Prince Philip are role models for what can be achieved if you are dedicated and committed and remain active," royal commentator Richard Fitzwilliams told AAP.
Since overtaking her great-great-grandmother Queen Victoria as Britain's longest reigning sovereign in 2015, the Queen has handed over more responsibilities to her son and heir Prince Charles as well as her grandsons, William and Harry.
But retiring completely doesn't appear to be an idea the Queen will entertain.
James Brookes of the news site Royal Central believes retirement would be "out of the question" for the Queen given her pledge to the Commonwealth as a 21 year old - five years before she ascended the throne - "that my whole life whether it be long or short shall be devoted to your service".
"Retirement for her would not really be an option because you can't really retire from being Queen - or king or monarch," he told Britain's Daily Express newspaper earlier this month.
But even if the Queen, who remains in excellent health, is reluctant to retire she has adopted a less hectic public schedule.
According to a tally of official engagements carried out by members of the royal family in 2017, the Queen's were scaled back to 296 from 332 the previous year.
Her eldest children Prince Charles, 69 and Princess Anne, 67 carried out the bulk of royal duties, with the heir to the throne notching up 546 while his sister completed 440 engagements, according to The Times.
Earlier this month Charles matched his mother in racking up 16 official visits to Australia when he opened the Gold Coast Commonwealth Games on her behalf before touring north Queensland and the Northern Territory.
The Queen's most recent tour Down Under was in 2011.
Charles's visit sparked another round of debate about whether Australia should cut ties with the monarchy and become a republic after the Queen dies or stick with it and have Charles as our head of state.
But the longest serving heir to the throne might have some work to do in convincing Australians to stick with the monarchy.
A Newspoll published by The Australian this month found 55 per cent of Aussies would want the nation to become a republic if Charles ascends the throne, with 35 against and 10 per cent uncommitted.
His next chance to brush shoulders with Australians will be when he represents the Queen at commemoration ceremonies being held at the Australian National Memorial, near Villers-Bretonneux in northern France on Anzac Day.
Charles's trip to France comes four days after the Queen's birthday celebrations, which include a concert at London's Royal Albert Hall where pop princess Kylie Minogue will perform alongside Sting and Tom Jones.
The next morning the Queen will push the start button for the 2018 London Marathon from the Quadrangle at Windsor Castle.
There's also the birth of her sixth great grandchild to look forward to this month, followed by Harry's wedding to American actress Meghan Markle in May.
The family celebrations continue in June when the royal family gathers for all the pomp and ceremony of the annual Trooping the Colour ceremony in London that marks the monarch's official birthday.
And as the Queen, surrounded by her family, watches the colourful display no doubt she'll ponder another busy year ahead.