When the British Royal Family abandoned all Germanic titles by Letters Patent issued by King George V in June 1917 , Prince Alexander of Teck adopted the surname `` Cambridge , '' became ( briefly ) Sir Alexander Cambridge , then the Earl of Athlone , relinquishing the title `` Prince of Teck '' in the Kingdom of Württemberg and the style `` Serene Highness . ''
When the British Royal Family abandoned all German titles by Letters Patent issued by King George V in June 1917 , Prince Alexander of Teck gave up the title `` Prince of Teck '' in the Kingdom of Württemberg and the style `` Serene Highness '' , and took the surname `` Cambridge , '' . For a short time he was known as Sir Alexander Cambridge , then the Earl of Athlone .