When Princess Elizabeth was born to the Duke and Duchess of York, she was third in line to the throne. Her father was the younger brother of David, the Prince of Wales, and it was assumed that the heir to the throne would eventually have children himself, and "Lilibet", as she was known, would not accede. No one had any idea then that she would go on to become the most enduring Queen in British history.
On 9 September Elizabeth II will become the country's longest serving monarch, breaking Queen Victoria's record. The foundations for her successful reign were laid in a childhood which was happy and secure.
The Queen enjoyed a happy and secure childhood
The Princess was very close to her parents and sister Margaret – or "us four", as her father dubbed them.
As a youngster she delighted in charades and acting and had an outdoorsy upbringing at Balmoral and in Windsor. Lilibet was also a keen swimmer, winning the Children's Challenge Shield at London's Bath Club.
The family's life changed forever in 1936, when Uncle David, now Edward VIII, abdicated in order to wed American divorcée Wallis Simpson. The shy Duke and his Duchess became George VI and Queen Elizabeth.
The Queen was very close to her parents and sister Margaret
It was an anxious time for Elizabeth's parents, and the young Princess was given the news by a footman that her father was to be crowned King.
"Does that mean that you will have to be the next Queen?" she was asked by her sister, Margaret.
Upon hearing that, yes, this would be the case, Margaret’s reaction was clear: "Poor you," she whispered quietly.
Elizabeth's father was crowned King George VI in 1936
Then came World War II and the girls' existence was turned upside down once again. With the entire nation saving and experiencing rationing, the young Princess decided to do her bit.
She joined the Auxiliary Territorial Services and trained as a driver, prompting her mother to complain: "We had sparking plugs last night all the way through dinner!"
Growing up during the privations imposed by war, Elizabeth had an upbringing which was frugal and focused on duty and family – values that have stood her in good stead in a life of service to the nation.