Officials discharged Prince Philip, the Duke of Edinburgh, from a London hospital Tuesday after he was admitted last week for treatment of an unspecified preexisting condition.
The 98-year-old duke walked out of the private King Edward VII Hospital of his own volition, according to The Associated Press.
Buckingham Palace officials said Philip returned Tuesday to Queen Elizabeth's Sandringham estate in eastern England, where the queen and her family traditionally celebrate Christmas, BBC News reported.
"The Duke of Edinburgh has today left hospital after being discharged by his doctor and is now back at Sandringham," palace officials said in a statement obtained by Sky News. "His Royal Highness would like to thank everyone who sent their good wishes."
Prince Charles told reporters Monday that his father was "being looked after very well in hospital," according to The Guardian.
“When you get to that age, things don’t work so well,” he said, according to the newspaper.
Officials declined to elaborate on the condition that prompted the duke's four-day hospital stay.
Philip retired from public life in 2017, though palace officials said at the time the decision was due to his age and not related to his health, the AP reported. He still appears alongside his wife and other members of the royal family at public events and church services, but he has not been seen in public since he attended Lady Gabriella Kingston's wedding at Windsor Castle in May, according to BBC News.
The duke underwent treatment in 2011 for a blocked coronary artery after complaining of chest pains, The Guardian reported. The next year, he was hospitalized for several days with a bladder infection, according to the newspaper.
He was also hospitalized in 2013 for abdominal surgery and in 2014 for surgery to his right hand, BBC News reported. More recently, in 2018, the duke was hospitalized to undergo surgery for his hip, CNN reported.