In 1940, heir apparent, together with her sister Princess Margaret (then 10), gave a wartime radio address to Britain’s children on BBC’s Children’s Hour. The black-and-white photos show the girls dressed in smart blazers, sitting at a desk in front of a microphone.

“We are trying to do all we can to help our gallant sailors, soldiers and airmen. And we are trying too, to bear our own share of the danger and sadness of war,” the then-Princess said in her speech. Her voice is bright and clear, tinged with youth and yet unwavering despite the somber times. It was an early precursor of the steady, devoted, determined, brave monarch she would become. During the war, Her Majesty marked her first solo public engagement when she attended a military inspection on her 16th birthday. She trained as a driver and mechanic in the Auxiliary Territorial Service and eventually attained the title of honorary junior commander.