King Charles appeared in high spirits on Sunday as he drove his wife Queen Camilla to church at Crathie Kirk near Balmoral.
The monarch, 75, was photographed behind the wheel looking smart in his trusty tweed coat, while Camilla, 76, looked her usual polished self in a crisp white shirt and pearl earrings.
The royal couple were spotted on what would have been the late Queen Elizabeth II's 98th birthday. To mark the occasion, Sarah, Duchess of York took to Instagram with a poignant message.
Alongside a joyous image of the late monarch dressed in lilac, Sarah, 64, wrote: "Today we are remembering Her Late Majesty Queen Elizabeth II on what would have been her [98th] birthday. Thank you for all that you have taught us, for being a steadfast leader and dear friend. You are sorely missed."
Charles and Camilla's church visit comes after they privately marked their 19th wedding anniversary, with Charles carrying out a brief engagement at Buckingham Palace where he was presented with the first banknotes bearing his portrait by the Governor of the Bank of England, Andrew Bailey.
It was a milestone moment for the monarch, who is undergoing treatment for an undisclosed form of cancer, to see his image on the new polymer notes, just over a year and a half since the start of his reign.
He is only the second British monarch to grace the Bank of England's notes – and it is the first time one sovereign's image has been replaced with another.
His Majesty has scaled back his public appearances amid ongoing treatment. At the time of his diagnosis, the palace released a statement which read: "During the King's recent hospital procedure for benign prostate enlargement, a separate issue of concern was noted. Subsequent diagnostic tests have identified a form of cancer."
Back in March, he made his first major public appearance since his cancer diagnosis was announced as he led the royals at the annual Easter Mattins service at St. George's Chapel in Windsor Castle.
He was joined by a number of senior royals including Princess Anne and her husband Sir Timothy Laurence, the Duke and Duchess of Edinburgh, Prince Andrew and Sarah, Duchess of York who all arrived shortly before the King and Queen.
The monarch is currently in Scotland, home to his beloved bolthole, Balmoral. And later this year, Charles is set to make history as he prepares to open his Scottish residence to the public for the first time since the castle was completed in 1855.
Guided tours of up to ten people will be available from 1 July to 4 August, before the King and Queen arrive for their annual summer break.
The idyllic estate has long been a firm favourite among the royals and was considered to be the place where the late Queen felt her "happiest". Princess Eugenie said of Her Late Majesty's love of Scotland: "I think Granny is the most happy there. I think she really, really loves the Highlands."