Prince William expressed that his late grandmother, Queen Elizabeth, would be "very proud" of King Charles after his coronation, as he honored his father during a concert at Windsor Castle on Sunday. The United Kingdom celebrated the newly crowned king with thousands of street parties across the nation.

King Charles and his wife Camilla were crowned at Westminster Abbey in London on Saturday, marking the nation's most significant ceremonial event in 70 years. A Buckingham Palace spokesperson said the royal couple was "deeply touched by the events of yesterday" and "profoundly grateful both to all those who helped to make it such a glorious occasion and to the very many who turned out to show their support."

King Charles, Camilla, and other senior royals joined 20,000 public members and invited guests for the "Coronation Concert" at Windsor, west of London.

"As my grandmother said when she was crowned, coronations are a declaration of our hopes for the future. And I know she's up there, fondly keeping an eye on us, and she'd be a very proud mother," Prince William said during a speech at the concert, eliciting cheers from the audience.

William paid tribute to his father's service and praised others, such as teachers and hospital workers, who have been striking in recent months.

The concert featured performances by Lionel Richie, Katy Perry, Andrea Bocelli, Take That, and pianist Lang Lang, as well as appearances by Tom Cruise and Winnie the Pooh.

The celebrations extended to the "Lighting up the Nation" event, where landmarks and natural beauty areas across the country were illuminated by projections and laser displays.

On Sunday, Prince Edward, Princess Anne, Princess Beatrice, and Princess Eugenie attended "Big Lunch" events, joining approximately 50,000 street parties held throughout the country. Prime Minister Rishi Sunak hosted a coronation lunch, which included Ukrainian families, youth groups, and U.S. first lady Jill Biden.

In east London, local councillor Joe Walker spoke of the coronation's unifying effect as the nation recovers from the COVID-19 pandemic and subsequent economic challenges.

However, not everyone celebrated the coronation. Anti-monarchists claimed that the "right to protest peacefully in the UK no longer exists" after some activists were detained for hours on Saturday. Police asserted that they believed the protesters intended to disrupt the royal procession. Culture Minister Lucy Frazer stated that she believed the police had "managed to get that balance right" overall in response to questions about the proportionality of the police response and its impact on free speech.