Celebrations marking the Queen's Platinum Jubilee have kicked off in London and around the United Kingdom, with huge crowds lining the streets of the British capital to catch a glimpse of the festivities.
The Queen appeared on the balcony of Buckingham Palace with other working royals as the Royal Air Force performed a fly-over featuring the Red Arrows aerobatic flight team as well as historic military aircraft.
It was her second public appearance of the day — earlier she appeared with a beaming smile alongside her cousin, the Duke of Kent, on the same balcony to welcome the crowds.
Wearing a pale blue outfit that she also wore for her official Jubilee portrait, she used a walking stick to make her way out onto the balcony.
Buckingham Palace said the Queen had experienced some "discomfort" at the day's events and would not attend a church service to mark her Platinum Jubilee.
It was with "great reluctance", the palace said, the 96-year-old monarch decided to skip Friday's service at St Paul's Cathedral.
"The Queen greatly enjoyed today's birthday parade and fly-past but did experience some discomfort," the palace said.
Thursday marks not only the start of the Jubilee, but also the 69th anniversary of the coronation of Elizabeth, who became Queen on the death of her father George VI in February 1952.
The Platinum Jubilee will feature four days of parties, parades and pomp to pay tribute to the 96-year-old monarch and her 70-year reign on the British throne.
The celebrations began on Thursday morning with Trooping the Colour, a military parade performed by members of the British Army which dates back to the 17th century.
Part of the parade was interrupted by several protesters, who jumped crowd barriers and ran out onto the Mall boulevard in front of Buckingham Palace and laid on the road in front of a marching band.
Police were quick to drag the men away.
By mid-morning police were forced to warn people to stay away from the event, with viewing sites quickly filling up.
"The viewing areas in central London for the Queen's Platinum Jubilee celebrations are now full," the Metropolitan Police said in a statement.
"To avoid the disappointment of not being able to enter the viewing areas please avoid the area."
Earlier on Thursday, the Queen thanked those involved in the celebrations to mark her Platinum Jubilee.
"I continue to be inspired by the goodwill shown to me, and hope that the coming days will provide an opportunity to reflect on all that has been achieved during the last 70 years, as we look to the future with confidence and enthusiasm."
The arrival of the first senior royals in a carriage — Kate, the wife of Prince William, her three young children and Camilla, the wife of heir to the throne Prince Charles — were met with loud cheers.
Prince Charles, 73, Prince William, 39, and the Queen's daughter, Princess Anne, arrived on horseback.
Charles and William will carry out other ceremonial duties on the Queen's behalf, although much attention will be focused on those who will not be present.
Second son Prince Andrew, 62, who settled a US lawsuit in February in which he was accused of sexually abusing American woman Virginia Roberts Giuffre when she was 17, did not attend.
It was revealed later on Thursday that Andrew, the Duke of York, would not attend Friday's National Service of Thanksgiving after testing positive to COVID-19.
The BBC said it was understood the duke had met with the Queen in the last few days but not since he had tested positive.
Prince Harry, now living in Los Angeles with his wife Meghan, attended the parade but was absent when the royal family gathered on the palace balcony to watch the fly-past.
'Our duty to come and celebrate'
As the planes flew overhead crowds cheered loudly and waved Union Jack flags.
Tens of thousands packed into the gardens and streets surrounding the palace to get a glimpse of the military parade.
Brisbane couple Sheryl and Morris Blanchard extended their holiday in London to attend the jubilee and described the moment as a "once in a lifetime experience".
"We just had to come, no one does the pomp and ceremony like the British do," Ms Blanchard said.
Catching a glimpse of the Duchess of Cambridge and her children was a highlight for Ms Blanchard.
"Seeing the Royal family, particularly the beautiful Kate and the children, smiling and waving," she said.
"It was really fantastic."
Loyal monarchist Robert Oliphant said it is a "historic and proud moment for all of Britain."
He travelled with his wife and dog Ruby more than 200 kilometres from Nottingham to attend the event, and was also present for the Queen's Diamond Jubilee 10 years ago.
"It's a one off, we won't see something like this again I believe," Mr Oliphant said.
Many other fans had travelled for days for the monumental occasion.
Natalie Pettit planned her vacation form Ohio in the United States to be in the UK for the anniversary.
"I think just being able to watch and see all the people coming together and flying flags and cheering is a really good feeling
It was disappointing day for some spectators who were not able to get close to parade or palace due to overcrowding.
Many in attendance had arrived in the early hours of the morning, while hundreds even camped overnight to get the best vantage point.
The Metropolitan Police were forced to close access to parts of the city due to the masses of people who came to celebrate.
Instead, hordes of people gathered in Parliament Square close to Big Ben to watch the military aircraft fly across the city for the parade's finale.
There were artillery gun salutes in London, across Britain and from Royal Navy ships at sea.
In the evening beacons will be lit across the country and the Commonwealth, with the Queen leading the lighting of the Principal Platinum Jubilee Beacon at her Windsor Castle home.
French President Emmanuel Macron, Pope Francis and former British prime ministers were among those sending messages of goodwill.
"I cannot think of any other public figure, any other celebrity, any other president … who could possibly have remained so popular," former prime minister John Major told BBC radio.
ABC with wires
