Princess Anne's new portrait by Swannell give an intimate glimpse of the "hardest-working" royal and is the second official image released for her 75th birthday. On Aug. 8, one week before the big day, Buckingham Palace unveiled a new tiara portrait of Anne with her husband, Vice Admiral Sir Timothy Laurence.

Princess Anne, the late Queen Elizabeth's only daughter and a former Olympic equestrian, turns 75 on Friday, with little fanfare planned in keeping with the royal's disdain for making a fuss.

Princess Anne has been pictured in a dignified new official portrait to mark her milestone 75th birthday. The Princess Royal, long celebrated as the hardest working member of the Firm, sported a characteristic cheeky grin in the image.