Prince Bertil was popular in Sweden where he was dubbed "Prince Charming" by the media for his long romance with Lilian.

CNN: Sweden's Princess Lilian dies at the age of 97

In 1943, she met Prince Bertil at the Les Ambassadeurs nightclub in the English capital, where he was stationed at the Swedish embassy.

BBC: Princess Lilian of Sweden: Swansea pays tribute

Prince Bertil's two brothers had already renounced their right to the throne by marrying commoners and the only heir, his older brother Crown Prince Gustaf Adolph, died in a plane crash in 1947.

CNN: Sweden's Princess Lilian dies at the age of 97

With a strong possibility that Prince Bertil would have to act as Regent to the present King Carl XVI Gustaf, who was less than a year old when his father was killed, the couple did not marry.

CNN: Sweden's Princess Lilian dies at the age of 97

In 1947, Bertil's eldest brother, Crown Prince Gustaf Adolf, died in a plane crash, leaving behind an infant son who would one day inherit the throne.

BBC: Princess Lilian of Sweden: Swansea pays tribute

Hugely popular in Sweden for his romance with Lilian and known as "the prince of cars" for his love of fast vehicles, Bertil died in 1997 aged 84.

BBC: Princess Lilian of Sweden: Swansea pays tribute

The prince's father, King Gustaf VI Adolf, refused to give his blessing to a marriage between Bertil and Lilian, so as not to jeopardise the future of the monarchy.

BBC: Princess Lilian of Sweden: Swansea pays tribute