For the Queen, tomorrow marks the beginning of her reign and the day she lost her beloved “Papa”.

George VI, who was suffering from lung cancer, died unexpectedly, but peacefully, in his sleep at Sandringham in 1952.

The Queen normally spends the joint anniversary of her accession to the throne and her father’s death in private at the Norfolk retreat, staying out of the public eye.

This year, February 6 will officially signify the monarch’s Sapphire Jubilee – 65 years to the day that she became Sovereign.

When her father died, Princess Elizabeth was thousands of kilometres away in Kenya, watching big game in the Treetops Hotel with the Duke of Edinburgh, unaware of the duty that had fallen upon her shoulders.

They were resting after returning to the Sagana Lodge which had been given to them as a wedding present by the people of Kenya when the message was given to Philip by his equerry and friend Mike Parker.

The Duke looked as if half the world had been dropped on him, his close aide once said.

Philip broke the sad news to his wife while they were alone. Princess Elizabeth, now Queen, was ready to fulfil her duty.

Close to her father as a child, Elizabeth was said to be similar to him in character and, according to royal author Sarah Bradford, they shared a “dedicated professionalism”.

Lord Charteris, her then-private secretary, remembered seeing her seated at her desk in the Lodge appearing “very composed, absolute master of her fate”.

Asked what name she wished to use as Queen, she is said to have replied simply: “My own name, of course.”

The remainder of the Commonwealth tour was immediately cancelled and swift arrangements were made for their return home.

After a long plane journey, the young Queen – a slim, pale figure, dressed in mourning black – made her way down the steps, ahead of the Duke of Edinburgh, and set foot on British soil on February 7 for the first time as sovereign. Prime Minister Winston Churchill was the first to greet her on the runway at London Airport.

Elizabeth had left as a Princess and returned as a Queen at the age of just 25.

Crowds gathered in the streets to solemnly watch the new monarch being driven past in a black Rolls-Royce.

On February 8, Elizabeth II was formally proclaimed Queen in St James’s Palace at a meeting of the Accession Council to which all members of the Privy Council were summoned.

In recognition of her 50 years on the throne in 2002, the Queen spent the Golden Jubilee accession day opening a cancer unit in memory of her father.

In 2012, on her Diamond Jubilee accession day – 60 years as monarch – she issued a message in which she promised to renew her pledge to serve the nation and its people.

– AAP