July 18 marks 68 years, five months and 12 days since the Queen succeeded to the throne following the death of her father, King George VI

Queen Elizabeth is about to claim another historic first: 25,000 days as sovereign.

The record-breaking royal — already the longest-reigning monarch in British history — will reach the mark on Saturday, July 18 — 68 years, five months and 12 days after she succeeded to the throne following the death of her father, King George VI.

In typically understated style, the 94-year-old Queen will be "spending the day privately," a Buckingham Palace spokesperson confirmed to PEOPLE.

Elizabeth was just 25 years old when she received news of her father's death at the remote Treetops camp in the foothills of Mount Kenya on Feb. 6, 1952.

RELATED: How Queen Elizabeth Is Keeping Calm & Carrying On at 94: 'She Has Impeccable Judgment'

Queen Elizabeth
Queen Elizabeth
| Credit: Toby Melville - WPA Pool/Getty Images
Queen Elizabeth II
Queen Elizabeth disembarking a plane after the death of her father.
| Credit: OFF/AFP/Getty

She was officially crowned the following year on June 2, 1953, at Westminster Abbey, London and has sat on the British throne ever since, passing the longevity record in 2015 previously set by her great-great grandmother Queen Victoria.

"It is not one to which I have ever aspired," Elizabeth said about claiming the record during a speech in Scotland alongside husband Prince Philip, 99. "Inevitably, a long life can pass by many milestones; my own is no exception," she added.

Anne Christened
Queen Elizabeth and Prince Philip at the christening of their daughter, Princess Anne.
| Credit: Topical Press Agency/Getty

The Queen's 25,000-day reign has seen her enjoy four children, eight grandchildren, and eight great-grandchildren. She has also met 12 U.S. Presidents, visited more than 120 countries and invited 14 different British Prime Ministers to form a government.

The first of these, Sir Winston Churchill, died in January 1965 as the Queen approached her 5,000-day mark. During the same year, Lyndon Johnson held his second inauguration, Julie Andrews starred in The Sound of Music and Bob Dylan recorded "Like a Rolling Stone." It was also the year of Selma.

Princess Anne, Queen Elizabeth, Prince Charles, Prince Philip, Prince Andrew and Prince Edward in 1965
| Credit: STRINGER/AFP/Getty

The Queen's 10,000th day — June 24, 1979 — was also overshadowed by a huge personal loss: the assassination  of her close cousin, Lord Mountbatten, on August 27 in Ireland.

That year, the Queen also welcomed Margaret Thatcher, her first female Prime Minister, to Buckingham Palace.

Queen Elizabeth PMs
Margaret Thatcher and Queen Elizabeth

The Queen's 15,000th day on March 2, 1993 was bittersweet. Despite widespread celebrations for the 40th anniversary of her coronation, the royal year was overshadowed by the announcement in January that Princess Diana wished to divorce her eldest son and heir, Prince Charles.

Prince Harry Commissioned Officer At Sandhurst
Prince Harry is commissioned as an officer at Sandhurst while his grandmother the Queen looks on.
| Credit: Tim Graham/Getty

Day 20,000 of the Queen's reign proved mundane. The Court Circular shows her visiting the warship HMS Lancaster on November 9, 2006.

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The year also saw Prince Philip make a historic visit to the Republic of Ireland, and Prince Harry graduate as an army officer from Sandhurst military academy.