Queen Elizabeth II, Britain's longest-reigning monarch, has died aged 96.
The Second World War saw Her Majesty – known then as Princess Elizabeth – take on a whole new level of responsibility.
Through the conflict, Princess Elizabeth went from a young girl to embodying the British resilience during some of the darkest hours the country has ever experienced, even becoming the first female member of the Royal Family to join the Armed Forces in a full-time active role.
- Queen Elizabeth II: The Armed Forces' Commander-in-Chief remembered
- The Queen and Prince Philip's fateful 1939 meeting at Dartmouth's naval college
- Remembering the Queen's first public address during WW2
When the war began in September 1939 she was just 13-years-old.
As Hitler's Nazi Germany swept through western Europe, children were evacuated from cities across Britain amid fears of German aerial attacks.
Princess Elizabeth was no different. Alongside her sister Margaret, they spent most of the Second World War at Windsor Castle, often away from their parents who stayed at Buckingham Palace.
In the biography, 'Elizabeth the Queen: The real story behind The Crown' by Sally Bedell Smith, Marie Antoinette de Bellaigue, who taught the two sisters French literature and history, said the siblings "never forgot there was a war on" but that there was "no feeling of doom and gloom".
Windsor Castle was turned into a fortress during the war to keep those inside safe.
The palace's windows were blacked out, reinforced with barbed wire and it was protected by batteries of anti-aircraft guns, Bedell Smith wrote.
Rooms were illuminated by bare low-wattage bulbs and hot water was so limited that lines were drawn at five inches in all bathtubs – although the biography stated that the family ate well.
As the war continued Princess Elizabeth became accustomed to what her mother described as "the whistle and scream of bombs", yet she was worried the sisters were "looking different" because "the noise of guns is so heavy" with much ordnance landing close to Windsor Castle – nearly 300 by the end of the war.
During the early stages of the conflict, Britain and its allies found themselves on the back foot.
They had been overwhelmed by Germany's blitzkrieg which had powered through countries like Poland, Czechoslovakia, Belgium, the Netherlands and, eventually, France.
The British Expeditionary Force, which had only arrived in France in September 1939, found itself seven months later pushed back to the port of Dunkirk, Normandy, and surrounded by advancing German forces.
Thanks to a miraculous effort involving civilian boats, as well as the French and Royal Navy, more than 338,000 British and Allied troops were rescued from the beaches.
Despite the success of the evacuation, it was clear Britain was not winning.
Keeping up morale was of vital importance – there was Forces' Sweetheart Dame Vera Lynn and, of course, the Royal Family, and in October 1940, aged only 14, Princess Elizabeth made her first public speech.
In an address broadcast on the BBC's Children's Hour radio programme, she sent her support to all youngsters evacuated from their homes across the country and the Commonwealth because of the conflict.
"Thousands of you in this country have had to leave your homes and be separated from your fathers and mothers," she said.
"My sister Margaret Rose and I feel so much for you as we know from experience what it means to be away from those we love most of all.
"To you, living in new surroundings, we send a message of true sympathy and at the same time we would like to thank the kind people who have welcomed you to their homes in the country."
She concluded her speech, by saying: "We know, every one of us, that in the end, all will be well; for God will care for us and give us victory and peace. And when peace comes, remember it will be for us, the children of today, to make the world of tomorrow a better and happier place.
"My sister is by my side and we are both going to say goodnight to you. Come on, Margaret. Goodnight, children."
The speech was made during the Battle of Britain which saw intense aerial dog fights over the skies of southern England between the Luftwaffe and the Royal Air Force.
Despite all the odds, the RAF won the three-and-a-half-month campaign.
The battle which, of course, came at a price with more than 300 RAF deaths, was a turning point for Britain and the Allies and ultimately scuppered Hitler's plans to invade.
Author Bedell Smith wrote that like much of her generation, Elizabeth was greatly affected by the war.
But she said her life at Windsor, if anything, gave her an early introduction to the male world she would later experience as Queen as she regularly mixed with young officers from the Grenadier Guards assigned to protect the Royal Family.
Throughout the war, the sisters also helped put on a series of pantomimes during the Christmas periods at Windsor, raising money for the Royal Household Wool Fund which helped soldiers on the frontline.
Occasionally, she would find out that officers she knew had died in battle.
Bedell Smith wrote that, while later in life friends would remark that the Queen found it almost impossible to write condolence letters about the deaths of those close to her, during World War Two, she would readily write to an officer's mother.
Elizabeth's nanny, Marion 'Crawfie' Crawford, said in Bedell Smith's biography that she would give the mother "a little picture of how much she had appreciated him [the officer] at Windsor and what they had talked about".
In 1942, Princess Elizabeth was given her first of many military titles.
She was appointed Colonel of the Grenadier Guards and on her 16th birthday in April, she carried out her first solo public engagement (as Princess Elizabeth) as she inspected the regiment at Windsor Castle.
The officers came to tea and more formal luncheons where Elizabeth arranged the seating and developed her skills as a hostess, Bedell Smith also noted.
Crawford said the princess had transitioned from "a rather shy little girl" to a "very charming young person able to cope with any situation without awkwardness", adding: "She was an excellent conversationalist."
This was just the start of her long affiliation with the Armed Forces and her official royal duties continued to increase from that point.
From March 1944, she began accompanying the King and Queen on tours within Britain and shortly after her 18th birthday that year, she was appointed a Counsellor of State during her father's absence as he visited Italian battlefields.
And for the first time, and certainly not the last, she carried out some duties as Head of State.
Later that year in December, she launched HMS Vanguard at Clydebank and flew her own personal standard for the first time.
It was also the first time the princess had travelled from London without the King and the Queen to take part in a ceremony of national significance.
Towards the end of the war, the princess joined the military, as so many had before her, as she wanted to contribute further to the war effort – going against the wishes of her father.
In 1945, Life Magazine published an article claiming King George VI believed that "her training as a princess outweighed the nation's increasing manpower problems and that 'Betts' should not join any of the women's auxiliaries, nor work in a factory".
However, she was eventually granted permission and joined the Auxiliary Territorial Service (ATS).
She completed her training at the ATS' No. 1 Mechanical Training Centre in Camberley, Surrey, where she learned to drive and maintain a range of vehicles.
The future Queen was made a Second Subaltern and by the end of the war had reached the rank of Junior Commander – the equivalent of captain.
Her career in the ATS meant she became the first female member of the Royal Family to join the Armed Forces as a full-time, active member and the only head of state to have served during World War Two.
While the women of the ATS were not allowed to fight, their role was important.
According to the National Army Museum, as well as being drivers and mechanics like the future Queen, ATS personnel also operated as telephonists, despatch riders, mess orderlies, postal workers, ammunition inspectors, searchlight operators, range finders and military police.
Their achievements also helped to pave the way for the establishment of the Women's Royal Army Corps.
At the time of 1945, newspapers dubbed Princess Elizabeth as the 'Princess Auto Mechanic'.
On VE Day in May 1945, she appeared on the balcony of Buckingham Palace to wave to the thousands gathered outside to celebrate Victory in Europe (VE) following the surrender of Germany.
She stood next to her mother, proudly, in her ATS uniform. But her celebrations did not end there.
The princess and her sister, then 14, were allowed out of the palace to secretly take part in partying.
She danced in delight outside Buckingham Palace with thousands of others revellers, slipping into the crowds unnoticed.
In an interview for the BBC Radio 4 programme The Way We Were for the 40th anniversary of VE Day, she recalled the celebrations which she described as "one of the most memorable nights of my life".
It was Margaret who came up with the idea, with the King and Queen agreeing to the excursion.
Under the cover of darkness, the royal teenagers moved around incognito in the mass of people.
They did the hokey cokey and the Lambeth Walk, sang Run Rabbit Run and Roll Out The Barrel, took part in chants of "We want the King" at the palace railings, and also danced the conga through The Ritz hotel in nearby Piccadilly.
As part of the official celebrations in 1945, King George VI and Queen Elizabeth made eight appearances on the palace balcony in 10 hours – on one occasion accompanied by Prime Minister Sir Winston Churchill.
Elizabeth and Margaret themselves appeared six times with their parents throughout the day and evening.
"We cheered the King and Queen on the balcony and then walked miles through the streets," the Queen said in the 1985 interview.
"I remember lines of unknown people linking arms and walking down Whitehall, all of us just swept along on a tide of happiness and relief."
The princess, who was still in her ATS uniform during the celebrations, described how she was terrified of being recognised on the streets "so I pulled my uniform cap well down over my eyes".
She was accompanied in a group of 16, which included Crawford, her cousin Margaret Rhodes, several Guards officers and the King's equerry.
The celebrations continued – according to 'Elizabeth the Queen: The real story behind The Crown', the princess recorded in her diary that the partying recommenced the following night.
"Out in crowd again," she wrote.
"Embankment, Piccadilly, Pall Mall, walked simply miles. Saw parents on balcony at 12:30am – ate, partied, bed 3am!"
Three months later, the future Queen again took to the streets to celebrate Victory over Japan (VJ) Day – effectively the end of the six-year war.
Elizabeth wrote that the group again "walked miles" and "ran through Ritz... drank in Dorchester, saw parents twice, miles away, so many people".
The 'Elizabeth the Queen: The real story behind The Crown' biography documented that, this time, she was recognised and cheered, but police cautioned party-goers that "the princesses wished to be treated as private individuals, and they were allowed to go on their way".