Queen Elizabeth partied for four days straight as a young princess to celebrate the end of World War II

Famed for being the perfect picture of proper, Queen Elizabeth does have a wild side, evidenced by the time she “partied and drank” for four days.

Queen Elizabeth is famously fond of booze and enjoys champagne after dinner most nights, apparently. Picture: AFP

Precision etiquette at all times, with tradition observed to the T, and not a hair out of place – Queen Elizabeth II is one of the most proper people in history.

But it seems the monarch once had a bit of a wild side when occasion called for it, evidenced by the time she “partied and drank” over four raucous days.

It was back when Her Majesty was Princess Elizabeth, the eldest daughter King George, and like the rest of Britain, got swept up in the ongoing celebrations marking the end of World War II.

And celebrate she did.

The then-19-year-old, who was the first female royal in history to be an active member of the armed forces, serving as a mechanic, kept note of her memories of that momentous period in her personal diary.

Extracts of the diary were published in the biography The Final Curtsey, penned by her cousin Margaret Rhodes, and with the Queen’s blessing.

They give a colourful insight into the mindset of the young royal, who a few short years later would begin charting a mighty course through history.

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The then Princess Elizabeth standing in front of an army truck during World War II, in which she served as a mechanic.

The young princess and future monarch during training, learning to change a wheel.

On May 8 in 1945, the princess listened to Prime Minister Winston Churchill announce via radio the “unconditional surrender” of Germany, marking the end of the war.

Britain erupted with joy and London broke out into spontaneous celebration.

“Sixteen of us went out in the crowd,” she wrote, adding that after cheering on her parents when they appeared on the balcony of Buckingham Palace, she and her friends went up St James Street in Piccadilly.

The next day, festivities continued throughout London and the young princess was once again part of it.

“Out in crowd again,” she wrote. “Trafalgar Square, Piccadilly, Pall Mall, walked simply miles. Saw parents on balcony at 12.30am – ate, partied, bed 3am!

Three months later for VJ Day, marking victory of Japan, on August 15, she was once again “out in the crowd” and partied through Whitehall, Pall Mall, St James Street, Piccadilly, Park Lane and Constitution Hill, she wrote.

She and her group of friends even “ran through (the) Ritz” before they “walked miles, drank in Dorchester” and then joined crowds outside Buckingham Palace – shoulder-to-shoulder with “so many people” – to wave up at her parents.

Among the revellers who spent nights partying in London to mark the end of World War II was a young princess, set to become the future Queen Elizabeth II.

The very next day, the future Queen was “out in the crowd again” but it was raining, “so fewer people”.

That didn’t dampen her spirits, though, with her diary entry recording that she conga danced into Buckingham Palace with her friends and sang until 2am, before eventually going to bed at 3am.

It’s incredible to imagine the heir to the throne being out and about in such chaotic conditions, but it was a time before a celebrity-like obsession with the royals.

Without things like social media, glossy magazines or even the widespread ownership of televisions, a young Princess Elizabeth might have gone largely unrecognised.

It helped that revellers were distracted by the happy end of a long and bloody war – and probably quite inebriated.

A film was inspired by her four nights of celebrating, called A Royal Night Out, released in 2015.

It tells of princesses Elizabeth and Margaret being permitted to venture outside the palace walls to mark the war’s end.

The rest of the plot is totally fictionalised – including the bits where the sisters are led astray by young military men and end up in all kinds of mischief … we presume.

But the rom-com borrows from an interesting footnote of history that would be otherwise forgotten.