Queen's 'Physical State and Resilience' During Rare Speech 'Was an Inspiration,' Her Biographer Says

Conjuring WWII-era decidedness, Queen Elizabeth’s rare address amid the coronavirus pandemic on Sunday captured the mood of Britain, a leading historian and royal biographer says.

The Queen, 93, referred to her wartime broadcast in 1940 alongside her sister Princess Margaret and said that Britons would “meet again” when it was all over. (“We’ll Meet Again” was a popular wartime song from Dame Vera Lynn.)

Summing up a spirit of “good-humored resolve” that people are showing during a time of lockdowns and separation from families, the monarch spoke of a generation that today is “as strong as any” — much has been said of her own wartime generation 80 years ago.

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“It brought a lump to my throat,” Robert Lacey, author of books Monarch and Majesty, tells PEOPLE. “It was interesting that she made the parallels with 1940, and then went on to explain that it was a different sort of international struggle now that everyone has to take part in. It made a perfect link to 80 years ago.”

“It was optimistic without false optimism. It was sober and realistic, but there was a grounded optimism to it.”

Despite relocating to Windsor Castle in mid-March and being rarely seen since, she was “looking very well. Her physical state and resilience was an inspiration in itself,” he adds.

Everett/Shutterstock Princess Margaret and Princess Elizabeth in 1940

The broadcast — shot last Thursday in the White Drawing Room — was watched by around 24 million people in the U.K. The country has a population of around 67 million.

Drawing a line from today back to her childhood, the Queen fondly recalled her broadcast as a teenage princess, during the war and holed up, during a time of crisis, at the castle. But that original broadcast might not have happened were it not for American inspiration.

Only two years earlier in 1938, the owner of the New York Herald Tribune, Helen Reid, had suggested that the two princesses might contribute to the cause of transatlantic solidarity, Lacey explains on his website.

“The British ambassador had been disdainful of such attempts to enlist the princesses for stunts, and George VI’s private secretary, Tommy Lascelles, agreed. There is, of course, no question of the princesses broadcasting,” he wrote, “nor is it likely for many years to come.”

The Royal Family/Youtube Queen Elizabeth

Lacey adds, “Two years later, with the Battle of Britain being fought overhead, Buckingham Palace took another view.”

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The Queen has made only a handful of similar addresses in times of crises over her 68-year reign – an incredible timespan that underlines yet again her iconic standing.

“She is living history and has always had this historical perspective about life,” Lacey tells PEOPLE. “And now she embodies history.”