Queen Elizabeth II will become Britain’s longest-reigning monarch later today, surpassing the record previously held by her great-great-grandmother Queen Victoria.

At about 17:30 BST (5:30 PM Nigerian time), the 89-year-old Queen would have reigned for 63 years and seven months – exactly 23,226 days, 16 hours and 30 minutes.

Queen Victoria, who previously held the record became queen at the age of 18 and ruled for 63 years, seven months and two days.

The UK Prime Minister will lead tributes at the House of Commons to commemorate the occasion. There will also be a salute by the River Thames where a flotilla of historic vessels, leisure cruisers and passenger boats will take part in a procession between the famous Tower Bridge and the House of Parliament.

The Queen, however will spend the day doing official duties in Scotland. The BBC is reporting that she does not want the day to be exceptional and has emphatically directed that she does not want a fuss to be made about the day.

She will be joined by the Duke of Edinburgh to open the £294m Scottish Borders Railway and make a steam train journey with Scotland’s First Minister Nicola Sturgeon, reports the BBC.

Buckingham Palace has released an official photograph taken in the Queen’s private audience room to mark the occasion. This is where she holds weekly audiences with prime ministers of the day, and receives visiting heads of state and government.

Queen Elizabeth’s reign has included 12 prime ministers, two more than served under Victoria.

Mr. Cameron described the Queen as having a “remarkable record” and “a symbol of Britain’s enduring spirit admired around the world”.

One of the Prime Ministers who served under her, John Major, described her as being “above politics.”

“The Queen is not part of politics. She is not party political, she is above politics. The monarchy wouldn’t be as popular if they were part of politics – they’re above and beyond it.

“But when the Queen meets her prime minister she has the opportunity to question, to ask, to counsel. Nobody knows and no prime minister is going to tell you exactly what happens at those meetings. So those who say she’s been too passive, how can they possibly know?”

However, anti-monarchist group, Republic, said the Queen’s long reign was a reason for reform not celebration.

Chief executive Graham Smith said: “It is now time for the country to look to the future and to choose a successor through free and fair elections, someone who can genuinely represent the nation.