Prince Philip spent a second night in hospital after being taken to the King Edward VII Hospital in London as a "precautionary measure" on Feb. 16.
Buckingham Palace revealed that the Duke of Edinburgh was admitted to the hospital on Tuesday evening. The statement revealed that the 99-year-old went to the King Edward VII Hospital "on the advice of his doctor, after feeling unwell." It was not an emergency situation.
The Queen's husband reportedly walked into the hospital by himself after travelling there by car, according to HELLO! UK. Additionally, Philip's stay is not related to COVID-19. He is said to be in "good spirits."
The duke is expected to stay in the hospital for a couple of days "for observation and rest," according to the Palace.
The retired royal has been admitted to the hospital before. In June 2017, the duke went to the King Edward VII Hospital for an infection, which arose from a pre-existing condition.
In December 2019, he returned to the same health care facility again for treatment for a pre-existing condition. The Duke of Edinburgh stayed there for four days before he was discharged and was able to spend the Christmas period at Sandringham, like the Royal Family typically does.
In early January, the Palace revealed Her Majesty and Philip had been vaccinated against COVID-19. They were inoculated at Windsor Castle, and the shots were administered by a Household Doctor.
The Queen has remained at Windsor Castle, where she and Philip had been spending the latest lockdown. They spent most of 2020 there as well.
On Feb. 17, the 94-year-old monarch carried out a virtual engagement. She spoke to Admiral Tony Radakin, the First Sea Lord of the Royal Navy.