But Louis’ special day isn’t the only milestone the British royals have commemorated in April: On the 21st, Charles, Camilla, William and Kate all gathered to mark what would have been Queen Elizabeth II’s 100th birthday. 

The day began with a tour for Charles and Camilla of the "Queen Elizabeth II: Her Life in Style" exhibition at The King's Gallery at Buckingham Palace. There, the couple enjoyed looking at more than 300 items from the late monarch’s personal clothing collection. 

The King and Queen also attended a viewing at the British Museum of a scale model of the forthcoming Queen Elizabeth Memorial, which is slated to be built overlooking The Mall in central London.

But the festivities didn’t stop there: That night, at Buckingham Palace, the Charles and Camilla were joined by Kate and William for a special reception celebrating Elizabeth’s centennial. 

In addition to partaking in a large sheet cake bearing the number 100, the royal family members enjoyed mingling with members of the late Queen’s charities and patronages, as well as members of the public who were also celebrating their 100th birthday on April 21. 

A video of the celebration shared to the Royal Family’s Instagram declared, “It was a delight to come together and share memories from the past 100 years!”

Charles also shared an additional video message reflecting on his late mother, who died in 2022 at the age of 96.

"Her near century was one of remarkable change," the 77-year-old said, "and yet, through each passing decade, through every transformation, she remained constant, steadfast and wholly devoted to the people she served."

"Millions will remember her for moments of national significance," he continued. "Many others for a fleeting personal encounter, a smile, a kind word that lifted spirits or for that marvelous twinkle of the eye when sharing a marmalade sandwich with Paddington Bear in the final months of her life."

For more news from the royal families around the world this year, read on.