Queen Elizabeth II is hours away from becoming the longest reigning UK monarch, clocking in at 63 years and 7 months of ruling over the Commonwealth.

At 4.30am on Thursday (NZ time) Elizabeth will overtake the record set by Queen Victoria, also making her the world's longest ruling female monarch.

A lot has happened in the last 63 years of Liz's life - the Cold War began and ended, humans landed on the moon, Princess Diana died, the internet was invented and Prince Philip offended pretty much everyone.

A portrait of Queen Elizabeth II taken in July 2015 and released by Buckingham Palace to mark the Queen becoming the longest reigning British monarch. Photo / AP
A portrait of Queen Elizabeth II taken in July 2015 and released by Buckingham Palace to mark the Queen becoming the longest reigning British monarch. Photo / AP

Before she became Queen, a 21-year-old Elizabeth promised the Commonwealth that "my whole life, whether it be long or short, shall be devoted to your service".

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Four years later, that long journey began when she was crowned Queen of England on February 6 1952 following the death of her father, King George VI.

And whether they agree with the concept of the monarchy or not, most people do concede Elizabeth has been true to her promise to devote her life to her role and her country.

She is the only female royal to have joined the British military and the only head of state alive to serve during World War II, something which helped earn her public support.

She was also an integral part of the ongoing transformation of the old British Empire into the British Commonwealth and its modern successor, the Commonwealth of Nations.

She acts as the host to the Heads of States of the Commonwealth realms, which includes New Zealand.

In 1991 she became the first British monarch to address the Unites States Congress, following the end of the Gulf War.

Queen Elizabeth II and Pope John Paul II as they meet at the Vatican. Photo / AP Photo
Queen Elizabeth II and Pope John Paul II as they meet at the Vatican. Photo / AP Photo

She also has a BAFTA award for her patronage of the film industry and was jokingly referred to as "the most memorable Bond girl yet" at the 2013 award ceremony.

Despite the social gaffes by members of her family - notable instances include her grandson, Prince Harry, dressing as a Nazi for a fancy dress party and a string of racist and otherwise offensive remarks made by her husband, Prince Philip over the years- the Queen herself has generally managed to stay in the public's good graces through her wise and generally unpolitical rule.

Diana, Princess of Wales, left, and Britain's Queen Elizabeth II as they smile to well-wishers outside Clarence House in London. Photo / AP
Diana, Princess of Wales, left, and Britain's Queen Elizabeth II as they smile to well-wishers outside Clarence House in London. Photo / AP

One blip occurred after the death of her daughter-in-law, Princess Diana in 1997, when the Queen's initial silence and decision not to fly the flag at half-mast at Buckingham Palace drew criticism.

Queen Elizabeth celebrated her Golden Jubilee in 2002 and her Diamond Jubilee ten years later, with celebrations held throughout the Commonwealth.

She has owned 30 corgis throughout her reign and has been head of state through 12 changes of Prime Minister.