Let the party begin! Kate, William and Harry lead the entire Royal Family as Queen kicks off her 90th birthday celebrations with a service at St Paul's Cathedral (and it's Philip's 95th birthday too!) 

Prince William, Prince Harry and the Duchess of Cambridge have helped kick-off the Queen's birthday celebrations this weekend by joining a star-studded crowd for a ceremony honouring her 90 years.

The young royals stole the show as they joined hundreds of politicians, dignitaries, celebrity guests and the extended Royal Family for a special thanksgiving service at St Paul's Cathedral, central London, this morning.

Looking resplendent in primrose yellow, Her Majesty gave fans a royal wave and appeared in great spirits as she arrived alongside the Duke of Edinburgh – who is celebrating his own 95th birthday today – for the 11am service.

The ceremony, led by the Archbishop of Canterbury Justin Welby and attended by a star-studded congregation including Princesses Beatrice and Eugenie, former prime ministers John Major and Tony Blair and television personalities Clare Balding and David Attenborough, kicks-off a three-day series of festivities in the capital to mark the Queen's birthday.

Princesses Beatrice and Eugenie, Prince Edward's children James and Louise , Prince Anne and Sophie, Countess of Wessex, and the Prince and Princess Michael of York were also in attendance - as were a host of politicians including David Cameron, George Osborne and Jeremy Corbyn.

During the special service, the Archbishop of Canterbury praised the way the Queen had ruled 'through war and hardship, through turmoil and change during the course of her 90 years' and asked the congregation to look back on her rule 'with deep wonder and profound gratitude'.

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It's my birthday! The Queen, looking resplendent in primrose yellow, was all smiles as she left the ceremony to mark her 90th birthday at St Paul's Cathedral today where the Archbishop of Canterbury praised her dedication and service to the nation in a heartwarming sermon

A royal turn-out: The Queen, clutching the Order of Service tightly in one hand, steadied herself with a handrail outside St Paul's Cathedral as she left the ceremony marking her 90th birthday. Right: Prince William and Kate smile as they leave the service alongside Prince Harry

Young royals leading the way: Prince Harry and the Duke and Duchess of Cambridge appeared in great spirits as they left the ceremony

Royal waves and beaming grins: Prince Harry left the service with the Duke and Duchess of Cambridge and all three were in great spirits

A right royal affair: Prince Charles and Camilla (together left) and the Duke of Kent (right) leave St Paul's Cathedral this afternoon 

Family day out: members of the royal family including (from left) Prince Andrew, his children Princesses Beatrice and Eugenie, Princess Edward and his son James, Princess Anne, Prince Edward's daughter Louise, Sophie Countess of Wessex and Autumn and Peter Phillips

Happy days: (From left): Prince Andrew, Princesses Beatrice and Eugenie, Prince Edward and his children Lady Louise Windsor and James, Viscount Severnand, and his wife Sophie Countess of Wessex all stand gleefully on the steps of St Paul's Cathedral following the service

A (Royal) family occasion: Prince Charles and Camilla (left) and Mike and Zara Tindall (right) appeared deep in thought after the service

Happy families: Prince Edward is pictured with his wife Sophie, Countess of Wessex, and their children James and Lady Louise

A big day: Prince Harry and the Duchess of Cambridge left St Paul's Cathedral with Prince William following the sermon by the Archbishop

Royal departure: The Duchess of Cambridge, pictured with William, looked stunning in an elegant dusty blue and white lace number

Splendid: The Queen and a rather happy Duke of Edinburgh thanked the Archbishop of Canterbury, Justin Welby, for his moving sermon

Stunning: This incredible aerial photograph shows the full congregation inside St Paul's during the ceremony to honour the Queen

The Most Rev Justin Welby praised the Queen's dedication and service to the nation and he rejoiced for the way 'God's loving care' had 'fearfully and wonderfully' sustained not only the monarch but the Duke of Edinburgh.

Leading figures from national life gathered for the service, which heralded the start of a weekend of celebrations marking the Queen's milestone.

Joining the royal birthday couple in the congregation was Prime Minister David Cameron, who gave a reading from the New Testament, the Prince of Wales, Duchess of Cornwall, Duke and Duchess of Cambridge and Prince Harry.

The world of politics was represented by former prime ministers Tony Blair and Sir John Major, senior figures from the Cabinet including Chancellor George Osborne, and Labour leader Jeremy Corbyn.

Governors general from the Queen's realms were also among those invited, along with faith leaders and hundreds of ordinary people nominated by Government departments to recognise their service.

Archbishop Welby began his sermon by telling the congregation of more than 2,000: 'Ninety years ago, Her Majesty The Queen was born, like every human being knit together in her mother's womb, and today we thank God for the way in which she, like every human being, is fearfully and wonderfully made.

'Before we ever come to light, God marks our journeys. No one at the Queen's birth knew for what she was destined. Today we recognise that God knew.'

He went on: 'We are here today to worship the God who made our Queen, and to celebrate the way in which God's hand has been so uniquely evident in her life.'

The Duchess has arrived: Kate was greeted with smiles as she entered St Paul's Cathedral for the service to mark the Queen's 90 years

Standing ovation: The congregation got to their feet as the Queen, elegant in primrose yellow, and Prince Philip arrived for the service

Happy faces everywhere! Mike and Zara Tindall appeared delighted inside the Cathedral while George Osborne spoke with Tony Blair

Familiar faces: Prince Harry and Camilla (right) were both in great spirits during the service which took place at St Paul's from 11am

A true gent: Prince William lovingly placed his hand on Kate's back as she made their way to their seats ahead of this morning's service

Moving: The Duke of Edinburgh appeared to stop and pay his respects as he made his way to the front of the Cathedral with the Queen

FULL TRANSCRIPT OF MICHAEL BOND'S REFLECTIONS ON PASSING OF THE YEARS READ BY DAVID ATTENBOROUGH

Sir David Attenborough read a passage by Paddington creator Michael Bond about the passing of the years and reaching 90

Here is the full transcript of Michael Bond's reflections on the passing of the years read by Sir David Attenborough during the St Paul's Cathedral national service of thanksgiving to mark the Queen's 90th birthday.

'Like me, author Michael Bond, the creator of Paddington Bear among other characters, also celebrated his 90th birthday this year. He reflects on the 1926 vintage and the passing of the years:

'I was born on January 13 1926. My mother took one look at the scales and decided to call it a day. I weighed over 11lbs so I was destined to be an only child at the outset. As a precaution she stood me in a bowl of Tidman's Sea salt to stop me going bandy with the weight, and it seems to have worked.

'Apart from an entry in the local paper it went unreported. The Times of London was more concerned with the fate of a bus conductor who was in court charged with allowing an excess of passengers to board an omnibus in East Ham. 'They swarmed on before I 'ad a chance to count them,' was his plea. Things moved at a different rate since those days.

'I was fortunate enough to be brought up in a house where books were part of the furniture. Mother was such an avid reader she wrote to authors to thank them and in the same letter ask if they could make the next book a little longer.

'My father's motto was 'the most precious gift you can bestow on a child is your time.' He was a very polite man and always wore a hat when he went outside in public in case he met someone he knew - even when paddling in the sea. That aside, he tended to be accident prone.

'For example: He rode a bicycle to work, and one day he managed to get both wheels caught inside a tram line. Instead of stopping there and then to unravel himself, he left it until he reached the depot, only to fall and break a collar-bone.

'And I clearly remember the day when he suggested a race. I got to the bottom of the garden and my father wasn't with me. He had set off at great speed with his head down to reduce resistance and ran straight into the garden shed. Flat on his back, he was muttering 'Strike me pink'.

'Mind you, addressing people older than yourself by their Christian name if you were a child could be a tricky business in those days which meant that most were either labelled an uncle or an aunty. Owing to the horrendous casualties in the First World War there were far more of the latter and because most of them led lonely lives I was frequently invited to stay while I was growing up. It was a mixed blessing.

'There was Auntie Emm, who insisted on giving me a daily bath. She smoked endless cigarettes whilst she was doing it and the ash used to fall all over me.

'Then there were two aunts who kept a dog kennels near Newbury's Greenham Common. Auntie Annie who brought everyone to attention whenever the National Anthem was played on the radio, and Auntie Gee, who was stone deaf.

'The latter loved going to the cinema, and as she was unable to lip-read from the picture on the screen Auntie Annie took a torch and shone the light on her own lips instead as she read the words out loud. Lovely ladies both, but ...

'Confusion was being piled on confusion.

'It wasn't until I reached the age of 90 that I began to realise the comfort of Louise Haskins's words suggesting that when you have a problem your best bet is to consult the man who stands at the gate of the year.

''Truly, if you put your hand into the Hand of God. That shall be to you better than light and safer than a known way'.' 

Happy Birthday Ma'am: The Queen, looking resplendent in canary yellow, gave a royal wave as she climbed the stairs of St Paul's Cathedral

In great spirits: The Duke of Edinburgh waved to royal fans alongside the Queen today as they prepared to enter St Paul's for the service

Let the celebrations begin: The Queen, head-to-toe in canary yellow, was joined by Prince Philip for the special ceremony at St Paul's

A special occasion: The Duchess of Cambridge stunned in a dusty blue and white lace ensemble as she arrived alongside her husband Prince William and brother-in-law Prince Harry for the thanksgiving service to mark the Queen's 90th birthday at St Paul's Cathedral

A royal wave: Prince Harry gives fans a nod as he arrives at St Paul's Cathedral with the Duchess of Cambridge ahead of the ceremony

The Royals: Prince William, Prince Harry and the Duchess of Cambridge (left) arrived together for the ceremony, which they seemed in good spirits for. Right: Prince William and his wife Kate share a joke with a member of the congregation, which includes dozens of celebrities

Having a splendid time: Prince Harry made the Duchess of Cambridge (left and right) howl with laughter once they were inside St Paul's

Leading the celebrations: Prince William, his wife Kate and Prince Harry led the way as they arrived at St Paul's Cathedral for the ceremony

Archbishop Welby read excerpts from Psalm 139 and told the congregation it explored 'fear and wonder, and the connection between them'.

He added: 'Over the 63 years and the 90 years there has been much to fear: at times of personal challenge or national crisis.

'But just as the Psalmist sees through fear to something more stirring and more extraordinary, so we look back on Your Majesty's 90 years in the life of our nation with deep wonder and profound gratitude.

'Through war and hardship, through turmoil and change, we have been fearfully and wonderfully sustained.'

Born Princess Elizabeth Alexandra Mary of York on April 21 1926 - the year of the General Strike - she was never expected to be Queen.

But she has become the longest reigning and oldest monarch in British history - and now the first to reach 90.

Over the decades, Britain has undergone major transformations from technological advances such as computers and supersonic flight to developments in society and the political landscape.

During her 64-year reign the monarch has been served by 12 prime ministers from Sir Winston Churchill to Mr Cameron, while Barack Obama is the 12th US president to hold office over the same period.

Archbishop Welby ended his sermon with the words: 'Your Majesty, today we rejoice for the way in which God's loving care has fearfully and wonderfully sustained you - as well as Prince Philip marking his 95th birthday today.

'And we rejoice, Your Majesty, for the way in which the life God has given you in turn you have given wonderfully in service to this nation.

'You have been an instrument of God's peace, and through you God has so often turned fear into wonder - and joy.' 

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It's mummy's birthday! Prince Charles and Camilla were all smiles as they greeted members of the congregation ahead of the service

A regal event: The Duke of Edinburgh and the Queen wave to royal fans who congregated outside of St Paul's Cathedral for the service

A princess affair: Princesses Beatrice and Eugenie (left) and Princess Anne (right) are all seen in the entrance of St Paul's Cathedral today

Star-studded: Lord Frederick Windsor, the son of Prince and Princess Michael of Kent, is pictured with his wife (left) Sophie Winkleman, Peep Show actress and sister of Strictly presenter Claudia Winkleman. His sister Lady Gabriella Windsor joined them (right)

A royal turn-out: Prince William, Harry and Kate were jubilant throughout the ceremony (left). Right: The Duke of Kent's daughter Amelia

A right royal procession: The Queen arrives with protection officers ahead of the thanksgiving ceremony in honour of her birthday

Her Majesty arrives: The Queen arrived at St Paul's about 10 minutes later after her car got stuck in traffic as it made its way across London

During the service, Sir David Attenborough also read Paddington Bear creator Michael Bond's personal account of growing up to be 90.

It was one of three birthday gifts featured in the ceremony for the monarch, and brought laughter from the congregation.

Sir David, who like the children's author turned 90 earlier this year, recounted one story about Bond's 'very polite' but accident-prone father, who always wore a hat, even when swimming in the sea, in case he met someone he knew.

He told the congregation: 'He rode a bicycle to work, and one day he managed to get both wheels caught inside a tram line. Instead of stopping there and then to unravel himself, he left it until he reached the depot, only to fall and break a collarbone.

'And I clearly remember the day when he suggested a race. I got to the bottom of the garden and my father wasn't with me.

'He had set off at great speed with his head down to reduce resistance and ran straight into the garden shed. Flat on his back, he was muttering 'strike me pink'.'

The congregation heard another birthday present for the Queen, the anthem I Love All Beauteous Things, written to mark the monarch's milestone by Judith Weir, Master of the Queen's Music, who set to music a poem by Robert Bridges, poet laureate in the year the Queen was born.

The final gift saw Martin James Bartlett, the BBC Young Musician of 2014, perform the piece Burlesque by Arnold Bax, who was the Queen's first Master of the Queen's Music.

Prayers were read for the Queen and among those asked to take part was Hilda Price, a 90-year-old widow who shares her birthday with the monarch.

The great-grandmother may have been born on the same day as the head of state - April 21 1926 - but the two women have lived very different lives.

Mrs Price, who lives in Cardiff, was born in a house in Carmarthen, while the Queen was born in a town house in London's Mayfair, and grew up to become the wife of the Rev Ken Price, who served in a series of parishes in the Welsh Valleys and surrounding areas.

The widow told the congregation: 'God our guide, we give you thanks for those who inspire us, encourage all people of faith that together we may embrace the future you have in store for us.'

It's MY birthday! The Queen was in good spirits as she arrived at St Paul's Cathedral, looking splendid in yellow, for her celebratory service

Kicking off the festivities: Prime Minister David Cameron and his wife Samantha have arrived alongside hundreds of politicians and dignitaries at St Paul's Cathedral to join the Queen and the extended Royal family for a special thanksgiving service for Her Majesty's 90th

Sharing a joke? David Cameron pointed out something in the Order of the Service to his wife Samantha and Chancellor George Osborne

Family affair: Mike and Zara Tindall arrive at St Paul's Cathedral for the national service of thanksgiving to celebrate the Queen's birthday

Celebrations: Zara Phillips and her husband, English former rugby player Mike Tindall, arrive to attend the special service at St Paul's today

Family turn-out: Princess Eugenie (left) was joined by her sister Beatrice (together right) for the special ceremony at St Paul's Cathedral

All smiles: Former Prime Minister Tony Blair had a huge grin on his face as he arrived alongside his wife Cherie for the special service

A fellow 90-year-older: David Attenborough arrives at the St Paul's service of thanksgiving for the Queen's 90th birthday celebrations today

Joining the congregation: Former Prime Minister John Major and his wife Norma Major were also among those to be invited to the service

Joining in the fun: Labour leader Jeremy Corbyn (right) John Bercow, the Speaker of the House of Commons, and his wife Sally (centre and left) take their seats for a National Service of Thanksgiving to mark the 90th birthday of Queen Elizabeth II at St Paul's Cathedral today

She was joined by five others who also read prayers, each of the five representing an aspect of the Queen's life from the law to the armed forces, the Commonwealth, her Royal Household and her love of horses.

Broadcaster Clare Balding, who has an association with the Queen as three generations of her family have trained horses for the monarch, represented the equine world.

The Queen's long life has seen her reign for more than 64 years - and after more than nine decades, she has become an enduring emblem of the nation.

The monarch turned 90 on April 21, but she traditionally has two birthdays - and celebrations for her official birthday will be marked by the Trooping the Colour ceremony being staged tomorrow.

Prince Philip celebrates his 95th birthday today, but he said he wants the focus to be on his wife. The Queen's consort was born on June 10, 1921 and his milestone will be marked with traditional gun salutes.

The ceremony got underway after the Queen's chauffeur driven limousine arrived more than 10 minutes after its scheduled time, following reports of traffic problems in central London.

As the royal couple stepped from the limousine and made their way to the steps of the cathedral's great west door, their presence was announced with a fanfare sounded by the state trumpeters of the Household Calvary, led by Trumpet Major Philip Bishop.

And as the monarch and Philip entered the place of worship, another was played by the Fanfare Trumpeters of the Band of Her Majesty's Royal Marines Portsmouth. 

'WE LOOK BACK WITH PROFOUND GRATITUDE': QUEEN'S DEDICATION TO THE NATION PRAISED BY ARCHBISHOP

Justin Welby, the Archbishop of Canterbury, praised the Queen's dedication and service to the nation during his sermon at St Paul's

Archbishop Welby began his sermon by telling the congregation of more than 2,000: 'Ninety years ago, Her Majesty The Queen was born, like every human being knit together in her mother's womb, and today we thank God for the way in which she, like every human being, is fearfully and wonderfully made.

'Before we ever come to light, God marks our journeys. No one at the Queen's birth knew for what she was destined. Today we recognise that God knew.'

He went on: 'We are here today to worship the God who made our Queen, and to celebrate the way in which God's hand has been so uniquely evident in her life.'

Archbishop Welby read excerpts from Psalm 139 and told the congregation it explored 'fear and wonder, and the connection between them'.

He added: 'Over the 63 years and the 90 years there has been much to fear: at times of personal challenge or national crisis.

'But just as the Psalmist sees through fear to something more stirring and more extraordinary, so we look back on Your Majesty's 90 years in the life of our nation with deep wonder and profound gratitude.

'Through war and hardship, through turmoil and change, we have been fearfully and wonderfully sustained.'

Archbishop Welby ended his sermon with the words: 'Your Majesty, today we rejoice for the way in which God's loving care has fearfully and wonderfully sustained you - as well as Prince Philip marking his 95th birthday today.

'And we rejoice, Your Majesty, for the way in which the life God has given you in turn you have given wonderfully in service to this nation.

'You have been an instrument of God's peace, and through you God has so often turned fear into wonder - and joy.'

Royal life: Prince William, Kate and Prince Harry were all in great spirits as they arrived to kick-off the Queen's 90th birthday celebrations

Ready to celebrate: Sophie, Countess of Wessex, looked lovely (left) while Princess Anne (right) appeared elegant in a cream number

Ready to celebrate? The Prince and Princess Michael of Kent looked a little stern as they made their way into the Cathedral for the service

Young royals leading the way: The Duchess of Cambridge (left) looked elegant in her dusk blue dress, tan shoes and matching clutch purse, while Lady Louise Windsor - the elder child and only daughter of Prince Edward - looked pretty in pink in a pastel dress (right)

Salute! Prime Minister David Cameron arrives in front of guards in full armour as he attends the thanksgiving ceremony at St Paul's today

Special occasion: Samantha Camera looked stunning in a nautical blue-and-white dress with black hat and shoes as she arrived today

Collapse: One RAF airman appeared to collapse on the steps of St Paul's ahead of the special ceremony to commemorate the Queen's 90th

Oh no: The excitement was all too much for one member of the Armed Forces who appeared to collapse while standing guard at St Paul's

Waiting to greet the Queen and Philip, was the Archbishop of Canterbury Justin Welby, the Right Reverend Dr Richard Chartres, Bishop of London and the Chapter of St Paul's - seven clergy and laity who form the Cathedral's governing body.

The Royal Family were already seated under Sir Christopher Wren's famous dome as the Queen and her consort processed up the nave following senior clergy.

The Queen wore a primrose yellow coat and matching dress and hat by Angela Kelly.

After the opening hymn, O Worship the Lord in the beauty of holiness, the Dean of St Paul's, the very reverend David Ison, gave the Bidding.

He told the congregation: 'Most especially today do we give thanks for the length of years that has been granted to our most gracious Sovereign Lady, Queen Elizabeth: for her faithful devotion, dutiful commitment, loving leadership, gentle constancy, royal dignity and kindly humanity.

'And, as we give thanks for Her Majesty, so also do we give thanks for Philip, Duke of Edinburgh, and all the Royal Family: for mutual love and support and for service to this country and to the Commonwealth.'

Crowds had earlier gathered around the edge of Sir Christopher Wren's famous cathedral, and when they saw the royal group step off a coach they cheered.

Among the first to arrive at St Paul's was Peter Phillips and his wife Autumn, and his sister Zara Phillips.

Peter Phillips has been the driving force behind the Patron's Lunch, which will celebrate the Queen's patronage of hundreds of charities and organisations.

Former Prime Ministers Tony Blair and John Major also arrived at St Paul's for the service. 

Other members of the Royal Family who arrived for the service included the Duke of York and his daughters Princess Beatrice and Princess Eugenie.

The Earl and Countess of Wessex were with their children Viscount Severn and Lady Louise Mountbatten-Windsor, with Sophie wearing a Suzannah coat dress and a hat by Jane Taylor.

The Duke and Duchess of Cambridge and Prince Harry took their seats together and they were soon followed by the Prince of Wales and Duchess of Cornwall.

The service is just the start of three days' worth of celebrations in the capital to mark the monarch's big day.

Although her actual birthday was on April 21, the royal family will mark the milestone publicly with three days of pomp and pageantry in London this weekend.

There are plenty of opportunities for royal fans to take part in the celebrations as well- although some of the events are exclusive to the Royal Family and special guests.

The traditional Trooping the Color parade will be held Saturday, the queen's official birthday. The event is expected to draw throngs of Britons and visitors to Buckingham Palace for a possible balcony appearance by the senior royals. 

The new Mayor of London: Sadiq Khan and his wife Saadiya were among those invited to attend the ceremony to celebrate the birthday

A star-studded affair: Television personality Clare Balding (left) and former Prime Minister Tony Blair were among guests invited today

Standing guard: Bugglers wait for Queen Elizabeth II to arrive at the thanksgiving service for her 90th birthday at St Paul's Cathedral

Happy birthday to you! Fans made homemade banners and posters galore as they turned out in their droves to celebrate outside St Paul's

Three-day party: Royalists turned out with Union Jacks galore as they queued to get a glimpse of the Queen and Prince Philip - who is celebrating his 95th birthday today. Fans waved huge '95' balloons in honour of the Duke of Edinburgh but also had banners for the Queen

It's party time! Royal fans with Union Flags and the Australian flag cheer at the barriers ahead of the thanksgiving service at St Paul's today

But there's still time for a selfie! Two guests, looking elegant in flowing skirts, made time to pose for a picture at the foot of St Paul's steps

The military event will see 1,400 soldiers, 200 horses and more than 400 musicians turn out at Horse Guards' Parade with the Queen attending to inspect the troops.

It has been part of the monarch's birthday celebrations since the mid-1700s and will feature a fly-past by the RAF at around 1pm.

Thousands of people are expected to line the streets around Horse Guards Parade to see the pomp and pageantry, so arriving early is recommended.

Alternatively, a flotilla of ships will sail down the Thames on Saturday.

More than 30 vessels, including the Queen's barge Gloriana and Dunkirk little ships will join in the procession.

The festivities will then culminate on Sunday with a street party on The Mall, which will see some 10,000 people enjoy a picnic lunch and a special parade.

Tickets were balloted and have now all been issued, but those who aren't lucky enough to attend can still watch the fun on big screens in nearby Green Park and St James Park.

Another screen will be in place in Trafalgar Square, alongside a host of other entertainment including food stands, a football competition, dancing and royalty-themed games. 

Overcome by the occasion? The moment a young RAF officer FAINTS while standing guard outside St Paul's for Queen's 90th birthday service 

An RAF serviceman had to be led away by paramedics after fainting while standing guard outside St Paul's Cathedral today.

The incident happened shortly before the Queen - and hundreds of dignitaries, leaders and members of the Royal Family, arrived at the cathedral for a special thanksgiving service to kick-off Her Majesty's 90th birthday celebrations.

Those on duty maintained their professionalism and composure, helping the young serviceman - believed to be an RAF Airman - back to his feet before continuing to stand guard while he was led away.

The incident happened before Her Majesty - and hundreds of dignitaries, leaders and members of the Royal Family, arrived at the cathedral

Those on duty maintained their professionalism and composure, helping the young serviceman back to his feet

With temperatures of around 22C in London today, standing for hours in the heat - and full military uniform - took its toll on the guard, who was quickly helped away from the cathedral.

Prince William, Prince Harry and the Duchess of Cambridge led the arrivals at St Paul's Cathedral as they joined hundreds of politicians and dignitaries in supporting the Queen and the extended Royal family.

Queen Elizabeth II is celebrating her official landmark birthday with a three-day series of festivities, starting today with the special ceremony at St Paul's.

Today's incident comes just weeks after two guards had to be carried from Horse Guards Parade on stretchers after reportedly fainting during rehearsals for Trooping the Colour.

The two men were thought to have passed out on May 23 as members of the Household Division, the Queen's personal troops, practiced a impressive display ahead of Her Majesty's official birthday.

And just days earlier, a soldier fainted during a parade to mark the 300th anniversary of the Light Dragoons at Catterick Garrison barracks, North Yorkshire.

The royal guard was taken away by paramedics and police officers prior to the arrival of Her Majesty at St Paul's Cathedral, central London

The Queen's reign on our parade! Britain prepares for three days of pomp, pageantry (and a lot of bunting) to celebrate Her Majesty's 90th birthday

Royalists up and down the country are beginning three days' worth of celebrations today as the nation officially marks the Queen's 90th birthday.

There is a packed schedule of events for the monarch over the next few days as the Royal Family gathers for the official birthday festivities in London. 

A traditional service of thanksgiving, the annual birthday parade and a mass street party for 10,000 people will all be part of the celebrations to mark the milestone birthday of Britain's longest-reigning sovereign.

And there will even be an extension of pub opening hours on Friday and Saturday evening in a bid to help foster a party atmosphere.

Joining in on the fun: This map shows when and where some of the celebrations are taking place to mark Her Majesty's 90th birthday

Three-day party: Union flag bunting has been strung across Oxford Street and Regent Street in central London ahead of the festivities

Floral tributes: This stunning window display has been put up in John Lewis on Oxford Street to mark the Queen's milestone birthday