Prince Philip has been released from the hospital.
On Tuesday, the royal was seen leaving King Edward VII hospital in London around 9 a.m. after spending four nights in the facility to undergo precautionary treatment for a “pre-existing condition.”
“The Duke of Edinburgh has today left hospital after being discharged by his Doctor and is now back at Sandringham,” the palace said in a statement. “His Royal Highness would like to thank everyone who sent their good wishes.”
Palace officials didn’t give details about the condition the 98-year-old royal needed treatment for. However, his son, Prince Charles, told reporters that it was an age-related issue.
“When you get to that age, things don’t work so well,” he said on Monday, according to the Associated Press.
Buckingham Palace confirmed that Queen Elizabeth’s husband checked into a London hospital on Friday.
“The Duke of Edinburgh travelled from Norfolk this morning to the King Edward VII Hospital in London for observation and treatment in relation to a pre-existing condition,” the palace said in a statement. “The admission is a precautionary measure, on the advice of His Royal Highness’ Doctor.”
A royal source told PEOPLE that Prince Philip did not travel by ambulance.
“It was a planned admission, and he walked into the hospital unaided,” the source added.
Meanwhile, the 93-year-old monarch took her annual train ride from London to Norfolk, where she traditionally spends Christmas.
Queen Elizabeth’s husband — who retired from his public duties in August 2017 — has been plagued by health issues in recent years. He abruptly cancelled his appearance at the traditional Maundy church service that he was scheduled to attend with the monarch in March 2018. Philip also skipped Easter Sunday services last year ahead of the announcement that he underwent hip replacement surgery.
The royal has also been absent from Trooping the Colour celebrations since his retirement.
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However, the Duke of Edinburgh has been seen in public multiple times in the past year, often driving his car (despite a scary car accident in January that resulted in him voluntarily giving up his license) or on carriage rides on grounds of Windsor.
Prince Philip also makes time to attend family events, such as weddings. He was present at grandson Prince Harry’s nuptials to Meghan Markle in May 2018, granddaughter Princess Eugenie’s royal wedding in October 2018 and Lady Gabriella Windsor’s May 2019 wedding to Thomas Kingston.
He was also featured in an intimate photo after the birth of great-grandson Archie in May alongside the Queen, Prince Harry, Meghan Markle and Meghan’s mother Doria Ragland.