King Charles III marks his first year as monarch on Friday
King Charles III celebrated his 75th birthday with fellow 75-year-olds with a tea party at Highgrove Gardens. AFP News

On Tuesday, Buckingham Palace celebrated King Charles III's 75th birthday with a photo montage of his growing up years from 1948 to present time. The images featured several royal family members but noticeably did not include neither Kate Middleton nor Meghan Markle.

His Majesty was born the eldest of four children on Nov. 14, 1948 and the first picture was of him as a baby cradled by his mother, Queen Elizabeth II. Then there were photos of him from his toddler years to becoming an adult participating in royal engagements and eventually becoming a father and monarch.

The montage also included photos of him with Princess Diana and then with Queen Camilla and with his children, Prince William and Prince Harry. The tribute to His Majesty was posted on the official social media page of The Royal Family and included the caption: "Wishing His Majesty The King a happy 75th birthday."

While royal watchers enjoyed travelling down memory lane with the images, there were also those who pointed out the obvious absence of Kate Middleton and Meghan Markle in the photos.

One account took it upon itself to share pictures of the monarch with his first daughter-in-law and wrote on X: "You forgot a few pictures of his beloved daughter in law for our viewing pleasure. Here you go!"

Likewise, there are no photos of King Charles III with his three grandchildren with Prince William and Kate Middleton.

Instead, the Prince and Princess of Wales shared a lovely family photo with the monarch to wish him a Happy Birthday.

Little is known about King Charles III's relationship with his daughters-in-law though he has made public statements about them. In his first address to the nation as the new British monarch in September 2022, he announced that he had made Prince William and Kate Middleton the new Prince and Princess of Wales.

Likewise, he referenced Prince Harry and Meghan Markle as he expressed his love for the couple "as they continue to build their lives overseas". The Duke and Duchess of Sussex left their royal duties in 2020 and now live in Santa Barbara, California.

Moreover, the 75-year-old called the Princess of Wales his "beloved daughter-in-law" during his state visit to Kenya in October this year as he recalled how his son proposed to the princess during a vacation to the country.

On Monday, His Majesty kicked off his birthday celebrations by joining fellow 75-year-olds for a tea party organised by The Prince's Foundation at Highgrove Gardens. A video shared online by royal correspondent Victoria Ward showed him cutting into a cake after well-wishers joined together to sing "Happy Birthday".

"The event brought people together to celebrate their 75th birthdays and recognise their contributions to the community. The celebration also marked other 75th anniversaries taking place this year, including Windrush 75 and the NHS's 75th anniversary," according to Buckingham Palace.

Then on his birthday, King Charles III and Queen Camilla launched the Coronation Food Project with a visit to a distribution centre in Didcot, northwest of London. The initiative intends "to bridge the gap between food waste and food need across all four nations of the United Kingdom, helping people and helping the planet".

Their Majesties toured the centre, which has been operating since 2014 and has 50 staff and 150 volunteers. In 2022, the site "rescued and redistributed over 1,000 tonnes of food that would have otherwise gone to waste".

Then in the afternoon following their stop at Didcot, the Irish Guards Band welcomed King Charles III and Queen Camilla back to Buckingham Palace with a rendition of "Happy Birthday".

Well wishes and greetings have also since flooded social media on King Charles III's birthday on Tuesday. Aside from Prince William and Kate Middleton, it is unclear if other members of the royal family greeted him including Meghan Markle and Prince Harry, who denied he received an invite to his father's birthday celebration.