Prince William and King Charles send well wishes to Prince Harry on his 40th birthday.

On Sunday, Prince Harry celebrated his 40th birthday and received several noteworthy "happy birthdays."

Prince Harry, the younger son of King Charles III and the late Princess Diana, received more well wishes than expected, with both his estranged father and brother, Prince William, and sister-in-law, Kate Middleton, making surprising public remarks in celebration.

King Charles' office at Buckingham Palace shared a celebratory message across the royal family's social media accounts.

"Happy 40th birthday to the Duke of Sussex!" the caption of the post read, accompanied by a 2018 photo of a smiling Prince Harry during a visit to Dublin, Ireland.

The Duke of Sussex turned 40 years old today.

The royal family last publicly acknowledged the prince's birthday in 2021, a year after his and Meghan Markle's departure as senior royals. While public birthday remarks are usually reserved for working members of the royal family, there have been exceptions for significant birthdays.

According to The Mirror, Harry is expected to receive $8.5 million on his birthday, a bequest from his late great-grandmother's estate, which is more than what Prince William received when he turned 40 due to the latter's position as heir to the British throne.

Helena Chard, a British broadcaster and photographer, stated to Planet Chronicle Digital that William, 42, may become "disgruntled" due to his younger brother's tell-alls that have shaken the monarchy, and the substantial inheritance he is expected to receive.

"According to Chard, Harry has been critical and hurtful towards the royal family, while Prince Harry is thrilled to have won the top prize as he has always felt inadequate compared to Prince William."

Prince Harry's financial comfort will ease King Charles' relief that he won't need to write any more memoirs attacking the royal family, according to Chard.

According to People magazine, Prince Harry is celebrating his birthday in Montecito, where he has been living since 2020. It is expected that he will be surrounded by family and friends on his special day. It is believed that the prince will continue the celebration overseas with his close confidants.

The Duke of Sussex's representative did not promptly respond to Planet Chronicle Digital's inquiry for comment.

Planet Chronicle Digital's Stephanie Nolasco and Ashley Papa contributed to this report.