Princess Anne paid her brother King Charles a visit at Clarence House on Friday morning.
The King, 76, underwent a brief visit to hospital on Thursday over side effects from his cancer treatment. As a result, the Monarch had to cancel all his planned engagements in Birmingham today.
Despite this, Charles was in high spirits, waving to fans on Friday morning, as he left Clarence House in his black Audi. It is understood he is going to his Highgrove estate in Gloucestershire.
Moments earlier the Princess Royal was driven out of the residence in a black Bentley. The royal siblings shared an exceptionally close bond.
Charles' hospital visit
On Thursday night, Buckingham Palace revealed that the King "required a short period of observation in hospital" earlier that day.
The full statement read: "Following scheduled and ongoing medical treatment for cancer this morning, The King experienced temporary side effects that required a short period of observation in hospital. His Majesty's afternoon engagements were therefore postponed.
"His Majesty has now returned to Clarence House and as a precautionary measure, acting on medical advice, tomorrow's diary programme will also be rescheduled. His Majesty would like to send his apologies to all those who may be inconvenienced or disappointed as a result."
A spokesperson added: "His Majesty was due to receive Credentials from the Ambassadors of three different nations this afternoon. Tomorrow, he was due to undertake four public engagements in Birmingham and is greatly disappointed to be missing them on this occasion.
"He very much hopes that they can rescheduled in due course and offers his deepest apologies to all those who had worked so hard to make the planned visit possible."
Anne and Charles' special bond
With only 21 months between them, Anne and Charles couldn't be closer. Whenever the pair attend events together they are always captured having a whale of a time, making each other laugh.
But it isn't just their bond as siblings that connects them, as they also have a slew of shared interests.
Talking about their shared love of gardening, the King told Simon Armitage on Radio 4's The Poet Laureate Has Gone to His Shed: "My sister and I had a little vegetable patch in the back of some border somewhere. We had great fun trying to grow tomatoes rather unsuccessfully and things like that."
He went on to say: "There was a wonderful Head Gardener at Buckingham Palace, he was called Mr Nutbeam, rather splendidly. He was splendid and he helped us a bit, my sister and I with the little garden we had."
Charles and Anne are also both accomplished equestrians, a passion shared by nearly all senior members of the Firm.
Not to mention Anne is also the King's official bodyguard. When asked about whether she would ever retire during an official visit to Cape Town in January she replied: "It really isn't written in, no. It isn't really an option, no, I don't think so.