Kate Middleton, Prince William join King Charles in honoring Queen Elizabeth on what would have been 100th birthday

Charles also honored Elizabeth’s birthday with a touching video tribute.

“Today, as we mark what would have been my beloved mother’s 100th birthday, my family and I pause to reflect on the life and loss of a sovereign who meant so much to us all and to celebrate and knew the many blessings of her memory,” the monarch said in a video shared on YouTube Monday.

“Queen Elizabeth’s ‘promise with destiny kept’ shaped the world around her and touched the lives of countless people across our nation, the Commonwealth and beyond,” he added.

“Her near century was one of remarkable change. And yet through each passing decade, through every transformation, she remained constant, steadfast, and wholly devoted to the people she served.”

Charles, 77, said his late mother will be remembered by “millions” for her national significance as well as personal encounters they had with the queen.

“Much about the times we now live in, I suspect, may have troubled her deeply, but I take heart from her belief that goodness will always prevail and that a brighter dawn is never far from the horizon,” the dad of two said in his message.

“For, as a young Princess Elizabeth put it in her first ever public broadcast, aged just 14, we can each play our part ‘to make the world of tomorrow a better and happier place,’” he added.

“It is a belief which I share, with all my heart.”

Charles concluded his tribute by asking people to follow his mom’s example and strive “together towards a better, happier tomorrow” that is “rooted in peace, justice, prosperity and security.”

“In this, I renew my own solemn pledge of duty and service to you all. God bless you, darling Mama. You remain forever in our hearts and prayers,” he said.

On Tuesday, Charles honored his late mother hosting a reception at Buckingham Palace alongside his wife, Queen Camilla.

Several members of the royal family attended the event, including Charles’ eldest son, William, and his wife, Middleton.

Princess Anne; Prince Edward, Duke of Edinburgh; and Sophie, Duchess of Edinburgh; Prince Richard, Duke of Gloucester; Birgitte, Duchess of Gloucester; Princess Alexandra and Prince Edward, Duke of Kent also attended.

The group also included other centenarians celebrating their 100th birthdays. Guests enjoyed a birthday cake, decorated with the number “100” in gold.

Elizabeth died peacefully at her Balmoral home in Scotland on Sept. 8, 2022. She was 96.

Charles — who became king after his mother’s passing — said in a statement at the time that Elizabeth’s death was a “moment of great sadness.”