UK's Queen Elizabeth turns 95 on April 21

LONDON: At the end of March, Queen Elizabeth marked the centenary of the Royal Australian Air Force (RAAF) in her first public engagement of 2021 outside Windsor Castle.

Just nine days later, on April 9, her husband of 73 years, Prince Philip, would pass away.

He had been her constant companion and support since she ascended to the throne aged just 25 after her father George VI died suddenly in 1952.

Elizabeth was crowned the following year.

From a young, glamorous Queen, she has become the UK's longest-serving monarch.

With a reign that has so far lasted almost seven decades, she has seen governments rise and fall, entertained generation after generation of heads of state, and presided over a family with its own share of tragedy and controversy.

But the death of Prince Philip combined with more than a year of living through a pandemic is reminding the United Kingdom that the reign of the Queen, the only monarch most of her subjects have ever known, is finite.

That has triggered speculation about how long she will remain on the throne, what the monarchy will look like in the future and, for some, even whether it should continue to exist.

While most observers say the queen is unlikely to abdicate given her lifelong commitment to public service, she has already started to turn over more responsibilities to Prince Charles, her eldest son and at 72, the oldest heir to the throne in history.

That process is likely to accelerate following Philip's death.

"I think what we have to remember is that the Queen, from the point of view of being Head of State, is never off duty. You know, the famous red boxes containing state papers still arrive every day, but she has a day off for her birthday, a day off at Christmas, but otherwise they're still there," says Christopher Warwick, royal biographer.

"The Queen has always been able since childhood to compartmentalise things in her life. And she's very stoic and she will she will be coping with this in her own way. But this is not to underestimate the grief that she will be feeling."

This year's birthday will, of course, be overshadowed by the death of Prince Philip.

The then-Princess met her future husband during a royal visit to Dartmouth Naval College in 1939.

She was just a giddy teenager and Prince Philip was training to be an officer in the King's service.

Their engagement came on her 21st Birthday in April 1947.

The young British Princess Elizabeth and her distant cousin Philip from the Greek royal family looked like any other couple, happy to be together to show off the platinum and diamond engagement ring and, of course look forward to their wedding day.

That same year, on November 20, she and Philip were married in a massive ceremony, a colourful event which made worldwide headlines in the drab years following the Second World War.

Seventy-three years later, it was time to say goodbye to the man the queen called her "strength and stay," a source of emotional support in her often lonely job.

Her loss was underscored by Saturday's funeral at St. George's Chapel in the grounds of Windsor Castle, where the figure of a widow in black sitting all alone offered a glimpse of the next solitary phase of the queen's reign.

Coronavirus restrictions dictated that she was unable to mix with anyone outside her own household.

She famously referred to 1992 as an "annus horribilis" (Latin for "horrible year") after three of her children's marriages came to an end and a fire devastated Windsor Castle.

But Christopher Warwick doesn't think she will feel the same way about 2021.

"I don't think she'd think of it in terms of it being horrible. I mean, losing her husband goes beyond that," he says.

Elizabeth and Philip raised four children: His Royal Highness, the Prince of Wales, Prince Charles; Her Royal Highness, the Princess Royal, Princess Anne; HRH The Duke of York, Prince Andrew and HRH The Earl of Wessex, Prince Edward.

They are likely to be a great support to her as she navigates life as monarch without Philip by her side.

She shows no signs of emulating Queen Victoria, who retreated from public life when her husband, Prince Albert, died unexpectedly at the age of 42.

"Duty seems to be a word that lots of people don't know the meaning of these days and Prince Philip and the Queen were raised with it. This is what the queen has known all her life," says Warwick.

Questions about the end of the queen's reign will also fuel the debate over the long-term future of the monarchy, seen by many as a symbol of national unity but by others as an obsolete vestige of the nation's feudal history.

The BBC received more than 100,000 complaints about its decision to pre-empt popular TV programs for round the clock coverage of Prince Philip's death, the most it has ever received about a single programming decision.

While her popular grandson, Prince Harry, has stepped away from royal duties, the rest of the royals, backed by professional staff and advisers, are likely to rally round the queen and take on more duties. The bedrock popularity of the Duke and Duchess of Cambridge, together with their reliable ability to connect with the public, will also sustain the institution.