Prince Philip hasn’t been doing well lately. The 98-year-old retired royal has, reportedly, not been feeling so energetic in recent weeks.

A royal insider told The Sun that the Duke of Edinburgh suffered a bit of a wobble while staying in Sandringham. While there, the dad of four spends most of his days reading and pottering about.

“Until recently he has been very active — carriage riding, fishing at Balmoral and driving around royal estates — although he no longer drives on public roads following his crash in January. His mind is as sharp as ever,” the source said.

The insider went on to say that Prince Philip’s wife has become more isolated in recent months. She has been staying at Buckingham Palace away from her husband, which is a sacrifice that she needs to make because of her role and duty to the nation.

But one of the ways that the royal couple is staying in touch despite the distance is through their regular phone calls. However, details regarding Prince Philip and Her Majesty’s phone calls have not been disclosed to the public.

Meanwhile, Prince Philip’s health also became a cause for concern among royal fans after the recent Remembrance Day event. The last time that the Duke of Edinburgh attended the same event was two years ago after he retired from his royal duties.

During that time, the Duke of Edinburgh was photographed standing beside the Queen at the venue. But eagle-eyed royal watchers noticed that Prince Philip was leaning against the wall the whole time. This suggests that he was already feeling the strain of his delicate age even at 96 years old.

Since then, Prince Philip has not been spotted in public often. But, he still managed to attend the royal weddings of Prince Harry and Meghan Markle, as well as the nuptials of Princess Eugenie and Jack Brooksbank in May and October of last year.

Prince Philip Britain's Prince Philip, Duke of Edinburgh, in his role as Captain General, Royal Marines, attends a Parade to mark the finale of the 1664 Global Challenge on the Buckingham Palace Forecourt in central London on August 2, 2017. YUI MOK/AFP/Getty Images