The tragic death of Prince Philip's sister who was killed in a plane crash while giving birth

The 96-year-old British Royal family patriarch has a tragic past.

Closer Weekly reported that Prince Philip’s older sister died a tragic death on a foggy day in Belgium in 1937.

Prince Philip has lived a long and full life. After marrying Queen Elizabeth in 1947, the couple welcomed four children, eight grandchildren, and five great-grandchildren.

His older sister, Princess Cecilie of Greece and Denmark, was not as fortunate as him.

The two and their three siblings are the children of Prince Andrew of Greece and Denmark and Princess Alice of Battenberg.

Prince Andrew was the son of King George I of Greece, while Princess Alice was the great-granddaughter of Queen Victoria of England.

The family settled in Paris after they were exiled from Greece in 1922. Nine years later Cecilie married Georg Donatus, Hereditary Grand Duke of Hesse and had three children.

Tragedy struck on November 16, 1937, when Donatus and Cecilie departed Frankfurt, Germany en route to London for the wedding of Donatus’s younger brother Louis.

The flight operated by Belgian airline, Sabena, also had their three children, Donatus’ mother, Louis’ best man, the children’s nurse, and four crew members onboard.

The flight could not make the scheduled stop at Brussels, Belgium, due to bad weather. The pilot was forced to continue on to Ostend.

Due to heavy fog, the plane clipped a factory chimney resulting in a wing and an engine being torn away from the fuselage. The plane crashed into the ground killing all the 11 passengers onboard.

Donatus was only 31 years old at the time and Cecilie was just 26.

Cecilie was eight months pregnant at the time and a Belgian inquiry into the tragic incident revealed that the pilot was attempting to land because she was giving birth. Authorities later found the baby’s body in the wreckage.

The couple’s other child, Princess Johanna, died of meningitis in 1939 at the age of two.

Both Cecilie and Donatus were members of the Nazi Party. Photos from their funeral show Prince Philip surrounded by people performing the Nazi salute. However, he was only 16 at the time and he may want to forget the whole incident for various reasons.