06/07/2013 06:43 EDT | Updated 08/07/2013 05:12 EDT

Prince Philip in hospital for surgery today

Prince Philip is in a London hospital and scheduled for exploratory surgery today, three days before turning 92.

The Queen’s husband, who celebrates his birthday on Monday, is said to be having abdominal problems. Buckingham Palace says he is expected to be in the London Clinic for up to two weeks after surgery on Friday. The private hospital is a longtime favourite of the royal family.

Philip checked in after attending a garden party, at which he seemed to be in good spirits, at the palace on Thursday.

He had pulled out of one event earlier this week but later attended a service at Westminster Abbey to mark the 60th anniversary of the Queen’s coronation, though some noted he looked unwell and was coughing.

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“He sometimes looks a little gaunt around the eyes,” noted U.K.-based historian and royal biographer Hugh Vickers. “But he walks around like a man of 40. He’s incredibly live and very fit.”

“If you see him in his office it’s as if time hasn’t made any dent at all,” he told CBC News.

This is the fourth time Philip, who is the longest-serving royal consort in British history, has been admitted to hospital in the past two years. His recent health scares include a bladder infection that landed him in hospital twice last summer.

He also spent four nights in hospital in late 2011 after suffering chest pains. He was diagnosed with heart disease and had a coronary stent procedure.

The prince is known for his hectic schedule — he made seven public appearances over the past week — and at-times cantankerous personality.

He does not like hospitals, said Vickers.

“He doesn’t like doctors, hospitals or to be confined against his will,” he said, adding Philip would be “difficult to confine.”

“But if he realized it was important, he would be a good, and sensible and wise patient.”

The Queen is continuing with her engagements Friday, which include officially opening the BBC's new broadcasting complex in central London.

The Queen will be shown around the state-of the-art broadcasting centre — home to BBC News and World Service among others — by BBC director general Tony Hall and BBC Trust chairman Lord Patten, as well as meet journalists in the newsroom.