How did queen Elizabeth's father pass away?

Answer 1

He died in his sleep from a coronary thrombosis. He was relatively young at the time (56), but had been a heavy smoker, which likely contributed to his early death (he had already had a malignant lung tumor which had been removed).

Answer 2

King George VI was a heavy smoker who developed lung cancer and other physical ailments. He died of a coronary thrombosis on February 6, 1952. He was 56 years old.

Answer 3

56