HRH Prince George and HRH Princess Marina with their children HRH Prince Edward, HRH Princess Alexandra and baby Prince Michael. Tragically, on Aug. 25,1942 HRH the Duke of Kent( age 39) died in a military plane crash. HRH Prince Michael was only a few weeks old ,having been born on July 4,1942. HRH Princess Marina died (age 62) on Aug.27,1968,hours after it was announced that she had a brain tumour.