Mountbatten

When Philip became a British citizen, in 1947, he took Mountbatten as his surname.
Prince Philip, royal consort to Queen Elizabeth II, dies at 99|Adrian Higgins|April 9, 2021|Washington Post
In 1947, to pave the way for marriage to Elizabeth, he became a naturalized British subject, and adopted the surname Mountbatten.
A Very Unhappy 92nd Birthday for Prince Philip as He Recovers From Surgery in Hospital|Tom Sykes|June 10, 2013|DAILY BEAST
(He took the last name Mountbatten when he became a naturalized British citizen before marrying Elizabeth).
The Grand Old Duke of Edinburgh: Why Everybody Loves Phil|Tom Sykes|November 23, 2012|DAILY BEAST
He took the last name Mountbatten when he became a naturalized British citizen before marrying Elizabeth.
12 Juicy Bits From the Prince Philip Biography|Tom Sykes|November 14, 2011|DAILY BEAST

They rarely saw Philip, who spent his childhood at boarding schools or with his maternal uncle Dickie Mountbatten.
12 Juicy Bits From the Prince Philip Biography|Tom Sykes|November 14, 2011|DAILY BEAST
Philip told Charles that Mountbatten was dead and it was no good “snivelling” about this fact.
The Prince Turns 90|Tom Sykes|June 10, 2011|DAILY BEAST

British Dictionary definitions for Mountbatten

Mountbatten

/ (maʊntˈbætən) /

noun

Louis (Francis Albert Victor Nicholas), 1st Earl Mountbatten of Burma 1900–79, British naval commander; great-grandson of Queen Victoria. During World War II he was supreme allied commander in SE Asia (1943–46). He was the last viceroy of India (1947) and governor general (1947–48); killed by an IRA bomb

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