Members of the Royal Collection Trust staff pose for a photograph with the oil on canvas portrait, HRH The Prince Philip, Duke of Edinburgh, 2017, by Ralph Heimans, which forms part of the Prince Philip: A Celebration display in Windsor Castle, Britain, J
Members of the Royal Collection Trust staff pose for a photograph with the oil on canvas portrait, HRH The Prince Philip, Duke of Edinburgh, 2017, by Ralph Heimans, which forms part of the Prince Philip: A Celebration display in Windsor Castle, Britain, June 24, 2021. Reuters / PETER NICHOLLS

Britain's Queen Elizabeth may make her first public appearance in five months on Tuesday when the royal family and other dignitaries gather for a memorial service in honour of her husband Prince Philip, who died last year.

Philip, the Duke of Edinburgh, who was by his wife's side for more than seven decades, passed away at their Windsor Castle home in April, two months shy of his 100th birthday.

Only 30 mourners were able to attend his funeral service then due to strict coronavirus rules, which meant the queen poignantly sat alone as her husband of 73 years was lowered into the Royal Vault of St George's Chapel of the castle.

Tuesday's service of thanksgiving at London's Westminster Abbey will be a much bigger event, with Buckingham Palace saying the 95-year-old queen had been actively involved in its planning.

The monarch herself has been forced to cut back on her duties since she spent a night in hospital last October for an unspecified illness and was advised to rest, and there have been concerns about her health after she cancelled a number of planned engagements since then.

A palace source said she was hoping to attend the service in what would be her first appearance in public since falling ill.

The occasion will also be her second son Prince Andrew's first public outing since he made an undisclosed payment to settle a U.S. lawsuit over allegations he sexually assaulted a teenage girl decades ago, claims he denied.

Joining him in the congregation will be other senior royals, foreign kings and queens, friends of the late duke, politicians including Prime Minister Boris Johnson, military figures and more than 500 representatives from charities and other organisations he championed.

'RARE ABILITY'

"A man of rare ability and distinction, rightly honoured and celebrated, he ever directed our attention away from himself," David Hoyle, the Dean of Westminster, is due to say.

Philip, who married Elizabeth in 1947 at the Abbey where she was also crowned six years later, helped his wife adapt the monarchy to the changing times of the post-World War Two era as the loss of empire and the decline of deference challenged the world's most prominent royal family.

On their golden anniversary, she described Philip, who was known for his no-nonsense attitude and a propensity for occasional gaffes, as her "strength and stay".

Forced to carve out a role for himself as there was no clear precedent, he focused on helping young people through his Duke of Edinburgh Awards scheme, and promoting environmental issues.

It was "a long life lived fully", Hoyle will say.

The service for the life of one-time royal moderniser comes as his grandson and future king Prince William, 38, is also looking to move the monarchy into the future.

On Monday, three tabloid newspapers ran front page stories all quoting an unnamed source saying William and his wife Kate wanted to "rip up the rule-book" and do things differently after criticism that parts of their recent week-long Caribbean tour appeared "tone-deaf" and a throwback to colonial times.

"It is not a criticism of how it was done in the past. But times are changing," the source was quoted as saying.