LONDON (AP) — Queen Elizabeth II stepped gingerly onto the Buckingham Palace balcony Thursday, drawing wild cheers from the tens of thousands who came to join her at the start of four days of celebrations of her 70 years on the throne.

Her fans sported Union Jack flags, party hats, or plastic tiaras. Some had camped overnight in hope of a glimpse of the 96-year-old queen, whose appearances are becoming rare, and a chance to watch the Trooping the Color — a military parade that has marked each sovereign’s official birthday since 1760.

It was an explosion of joy in a massive crowd, one of the first big gatherings since the COVID-19 pandemic began more than two years ago.

“Everybody has got the same mission,” said Hillary Mathews, 70, who had come from Hertfordshire, outside London. “All the horrors that’s been going on in the world and in England at the moment are put behind us for a day, and we can just enjoy really celebrating the queen.”

Elizabeth, who became queen at the age of 25, is Britain’s longest-reigning monarch and the first to reach the milestone of seven decades on the throne.

She basked in her moment. Smiling, she chatted with her great-grandson Prince Louis, 4, who occasionally covered his ears as 70 military aircraft old and new swooped low over the palace to salute the queen. The six-minute display included a formation of Typhoon fighter jets flying in the shape of the number 70.

The queen, wearing a dusky dove blue dress designed by Angela Kelly, was joined on the balcony by more than a dozen royals — though not Prince Harry and his wife Meghan, who gave up front-line royal duties two years ago. The couple traveled to London from their home in California with their two young children to take a low-key part in the celebrations and watched Thursday’s Trooping the Color with other members of the family.

They did not appear on the palace balcony, because the monarch decided that only working members of the royal family should have that honor. The decision also, handily, excluded Prince Andrew, who stepped away from public duties amid controversy over his links with the convicted sex offender Jeffrey Epstein.

Andrew will also miss a service of thanksgiving Friday at St. Paul’s Cathedral in London after testing positive for COVID-19.

The jubilee is being commemorated with a four-day holiday extravaganza and events including a concert at Buckingham Palace on Saturday and a pageant staged by thousands of performers drawn from schools and community groups around the country on Sunday.

Thousands of street parties are planned nationwide, repeating a tradition that began with the queen’s coronation in 1953.

Not everyone in Britain is celebrating. Many people have taken advantage of the long weekend to go on holiday. And 12 protesters were arrested Thursday after getting past barriers and onto the parade route. The group Animal Rebellion claimed responsibility, saying the protesters were “demanding that royal land is reclaimed.”

Yet the jubilee is giving many people — even those often indifferent to the monarchy — a chance to reflect on the state of the nation and the huge changes that have taken place during Elizabeth’s reign.

Former Prime Minister John Major, one of the 14 prime ministers of the queen’s reign, said the monarch’s stoic presence had helped steer the country over the decades,

“The queen has represented our better selves for over 70 years,” he told the BBC.

In a written jubilee message, the queen thanked people in Britain and across the Commonwealth involved in organizing the celebrations. For many, the occasion is the first opportunity for a big bash since the start of the coronavirus pandemic more than two years ago.

“I know that many happy memories will be created at these festive occasions,” Elizabeth said. “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.”

Congratulations arrived from world leaders, including Pope Francis and U.S. President Joe Biden. French President Emmanuel Macron called Elizabeth “the golden thread that binds our two countries” and former President Barack Obama recalled the queen’s “grace and generosity” during his first visit to the palace.

“Your life has been a gift, not just to the United Kingdom but to the world,” Obama said in a video message, adding: “May the light of your crown continue to reign supreme.”

Cheers and the clop of hooves rang out Thursday as horse-drawn carriages carried members of the royal family, including Prince William’s wife, Kate, and their children Prince George, 8, Princess Charlotte, 7, and 4-year-old Prince Louis, from Buckingham Palace to Horse Guards Parade, a ceremonial parade ground about 1 kilometer (0.6 miles) away, for the Trooping the Color ceremony.

The annual tradition is a ceremonial reenactment of the way battle flags, or colors, were once displayed for soldiers to make sure they would recognize a crucial rallying point if they became disoriented in combat.

Prince Charles played a key role during the event as he stood in for his mother. Elizabeth has had trouble getting around of late, and her courtiers have been careful to keep make things as simple for her as possible, letting Charles take on more tasks..

Clad in his ceremonial military uniform, Charles rode onto the parade ground on horseback and took the salute of the passing troops in their scarlet tunics and bearskin hats. He was flanked by his sister, Princess Anne, and son Prince William.

Tens of thousands of locals and tourists lined the route between the palace and parade ground to take in the spectacle and the atmosphere.

“I was right at the front … I’m very proud of the queen,” said Celia Lourd, 60. “She’s been my queen all my life and I think we owe her an awful lot for the service she’s given to the country, so I wanted to come to show my support today and say thank you.”