London:
The Duke of Edinburgh, the 90-year-old husband of Britain's Queen Elizabeth II, underwent successful heart surgery Friday for a blocked coronary artery, Buckingham Palace said.
The duke underwent an "invasive procedure of coronary stenting" after being taken to hospital with chest pains, the palace confirmed.
"Following tests at Papworth Cardiothoracic Hospital in Cambridge this evening the Duke of Edinburgh was found to have a blocked coronary artery which caused his chest pain," the palace said in a short statement.
"This was treated successfully by the minimally invasive procedure of coronary stenting," it added. "Prince Philip will remain in hospital under observation for a short period."
In the procedure, a tube-like device called a stent is inserted into the blocked artery to open it up and help restore a healthy blood flow.
The duke, also known as Prince Philip, was taken by helicopter to Papworth Hospital from Sandringham House in Norfolk, southeast England, where the Royal Family was enjoying a Christmas celebration, British media reported.
The royals were spending their traditional Christmas holiday at the Queen's 60-acre (24-hectare) residence, where the Duchess of Cambridge is spending her first Christmas as a member of the royal family.
The prince, who is Britain's longest-serving consort, is well-known for his tireless spirit and outspoken views.
However, he has recently suffered occasional bouts of poor health and pulled out of a trip to Italy in October nursing a cold.
The duke received a front-page apology from the Evening Standard newspaper in 2008 after it incorrectly reported he had prostate cancer.
A chest infection hospitalised him the same year, but he went on to make a full recovery.
Margaret Holder, a royal commentator, told the BBC: "It's obviously very worrying for the queen and the rest of the royal family who are gathering at Sandringham for Christmas."
Philip was born into the Greek royal family in 1921 but was exiled from Greece, along with his family, when he was a child.
After studying in Britain and Germany, Philip joined the British Royal Navy in 1939 and served with the Mediterranean and Pacific fleets during World War II.
It was during his time in the navy that he began correspondence with Princess Elizabeth, who ascended to the British throne in 1952.
The pair became engaged in 1947 and married later that year at London's Westminster Abbey.
The queen and the duke announced earlier this week they were to "travel as widely as possible throughout the United Kingdom" next year to celebrate Elizabeth's diamond jubilee.
The prince is a staunch supporter of the armed forces and also lends his name to an award scheme aimed at helping young people.
He also maintains a keen interest in science, technology, industry and the environment, as well as sports from cricket and polo to equestrianism and flying.