Prince Philip has left the hospital 4 weeks after being admitted as a 'precautionary measure'

• Prince Philip has left the hospital four weeks after being admitted for treatment on February 16.
• The 99-year-old was being treated for an infection and a pre-existing heart condition.

The Duke of Edinburgh has left the hospital four weeks after he was first admitted under guidance from his doctor.

The 99-year-old husband of Queen Elizabeth II was photographed leaving King Edward VII's Hospital in London on March 16, where he was admitted on February 16 as a "precautionary measure" after feeling unwell.

"The Duke of Edinburgh has today been discharged from King Edward VII's Hospital and has returned to Windsor Castle, following treatment for an infection and a successful procedure for a pre-existing condition," Buckingham Palace said in a statement obtained by Insider.

"His Royal Highness wishes to thank all the medical staff who looked after him at both King Edward VII's Hospital and St Bartholomew's Hospital, and everyone who has sent their good wishes," the statement added.

Buckingham Palace initially said the duke was expected to remain in the hospital for "a few days of observation and rest."

However, he was later transferred to a specialist cardiovascular hospital on March 1, where he was treated for an infection and observed for a pre-existing heart condition.

He returned to King Edward VII's Hospital for further treatment on March 5.