The Queen’s daughter, Princess Anne, celebrated her 68th birthday in private with her loved ones on August 15. But the royal family did take to their official social media accounts to wish the Princess Royal’s a very happy birthday.

The Queen's Twitter account shared a beautiful photo of Her Majesty's daughter in a turquoise ensemble, taken in June when Anne attended Ascot.

The photo was caption: "Wishing HRH The Princess Royal a very Happy Birthday! #HappyBirthdayHRH

It was revealed earlier this year that Princess Anne is the hardest working royal, fulfilling 540 official duties so far this year. This feat did not go unrecognised by the royal family, who acknowledge the Queen’s daughters hard work.

"The Princess Royal has a busy schedule of engagements which see her travel widely across the UK and overseas. #HappyBirthdayHRH," the Royal Family captioned a series of snaps of Anne serving her royal duties.

The 68-year-old's tireless charity work as well as her love for equestrian were also acknowledged on her birthday.

Sharing a flashback photograph of Anne and one of her horses, the royal family wrote on Twitter: "Known for her love of horses and an equestrian career which saw her compete in the 1976 Montreal Olympic Games, Her Royal Highness is involved with riding for the disabled organisations across the Commonwealth."

Charles, The Prince of Wales, and Camilla, The Duchess of Cornwall, also took to their official social media account to share their well wishes.

"Happy Birthday to HRH The Princess Royal. #HappyBirthdayHRH," Clarence House captioned a picture from 2009 of Prince Charles and his sister laughing.