Queen Elizabeth 2 must have set many records in longevity. One of them was being the last surviving Head of State who saw service in World War 2:
Before her, the last surviving head of state who served in WW2 was George HW Bush (1924-2018). He served as a carrier pilot in the US Navy and saw active service, being shot down off the Bonin Islands off Japan.
He was the only survivor of a mission in which several of his comrades died in gruesome circumstances:
More details here about the Japanese atrocities:
Tail piece: Can you think of any prominent Indian political leader in recent times who had seen any significant military service?