Queen Elizabeth will become Britain's longest serving monarch today when she passes a milestone set by her great-great grandmother Queen Victoria.
The 89-year-old became Queen 63 years and 217 days ago after her father King George VI died in his sleep at approximately 1am on 9 September, 1953. It is estimated she will overtake Victoria at 5.30pm (BST).
Despite the milestone, Buckingham Palace has said the Queen will press ahead with her previously scheduled royal appointments, and along with the Duke of Edinburgh will visit Edinburgh, Midlothian and Tweedbank to officially open the new Scottish Borders Railway.
- Queen to overtake Victoria at 5.30pm
- Newspapers mark landmark with bumper issues
- Prime Minister David Cameron Tweets tribute
- MPs allotted time in House of Commons to make speeches
- Bad weather delays the Queen and Duke of Edinburgh
- The monarch boards the Union of South Africa for Tweedbank
More coverage of Queen Elizabeth II's record reign in our Flipboard magazine
Going to be shutting down the blog at the end of an eventful day. Here's to another 63 years.
AND SHE'S DONE IT!
With the time past 5:30pm, Queen Elizabeth II has officially become Britain's longest-reigning monarch.
Over on the Gov.uk website, historian and biographer D R Thorpe has written a post on the Queen's relationship with the 12 prime ministers who lead the country during her reign.
You can read the full post here.
While we wait for 5:30pm the time Buckingham Place has down as the official moment when the Queen will overtake her great-great grandmother's reign of 23,226 days, 16 hours and 23 minutes, here are some photos of her down the years.
More can be seen via our '63 years in photos' gallery.
More audio footage here, this time from people who have more unusual stories of meeting the square than the usual 'shook her hand at a hospital'.
Queen Elizabeth thanked the public for the "touching messages of great kindness" she has received during a rare speech at the opening of the Scottish Borders Railway. She spoke of her gratitude for the messages from home and abroad on.
Getting into the royal festivities is British Airways. To mark the 63 years since the Queen acceded to the throne the airlines is offering £63 off flights until midnight Wednesday 9 September 2015 - you can browse the long haul destinations here.
In case you missed the Queen's steam powered rail extravaganza earlier today, here's a photo gallery from the journey. After arriving at Waverley station in Edinburgh 40 minutes late due to fog at Balmoral, Queen Elizabeth and the Duke of Edinburgh joined Scotland First Minister Nicola Sturgeon on board the Union of South Africa to Tweedbank, where she unveiled a commemorative plaque.
Here is some reaction from the banks of the River Thames as the celebratory flotilla passed towards the Houses of Parliament.
As the Queen continues with her walkabout during this day, here are some of IB Times UK's video coverage of what has happened so far:
Queen Elizabeth II: Monarch rides steam locomotive to mark longest reign
David Cameron pays tribute to 'extraordinary' British monarch
The Queen's speech in full:
"The Duke of Edinburgh and I are delighted to be back in the Borders today and especially to have arrived by train. It is wonderful to have witnessed the excitement which the return of the railway has brought here.
We are very grateful for the warmth of your welcome on this occasion. Many, including you, First Minister, have noted another significance attached to today. Although it's not one to which I've aspired. A long life can pass many milestones. Mine is no exception.
I thank you all, and the many others at home and overseas, for your touching messages of great kindness."
As expected, the Queen only gave a few words to mark the "other significant" milestone today as well as the opening of the railway, which she described as "not one to which I've aspired".
The Queen has now arrived at Tweedbank to officially open to new Borders Railway. You can read the IB Times UK's report on the longest new domestic railway for more than a century here.
It is not known if the Queen will be saying a few words or not once she arrives at Tweedbank to mark the historic day.
While we wait for the Queen to arrive at the Scottish town of Tweedbank, Commonwealth Secretary-General Kamalesh Sharma has praised the monarch on behalf of the 53 countries which were formally part of the British Empire.
The Queen's personal commitment as Head of the Commonwealth is exemplary, and her devotion to advancing cooperation and understanding continues to inspire people of all ages Commonwealth-wide.
As a symbol of continuity during decades of unprecedented change, and by drawing our people together in their rich diversity, Her Majesty has embodied all that is best in the Commonwealth. With vision and dedication her example has encouraged successive generations of leaders and citizens to embrace the promise of the future.
In congratulating Her Majesty on this historic occasion the Commonwealth joins with a fresh sense of common purpose, committed to advancing in practical ways the shared values and principles now set out in the Commonwealth Charter.
There are now 53 Commonwealth member states, compared to eight when Queen Elizabeth II became Head of the Commonwealth in 1952.
Until the Queen arrives at Tweetbank, take a look back at some of IBTimes UK's coverage so far of the Queen's record reign.
- The Queen shuns TV address but could mention record at Scottish Borders Railway
- Ten things you didn't know about the British monarch
- What was Britain like in the 1950s?
- What are the Imperial State Crown, orb and sceptre used at Coronation?
- Chelsea pensioners recall Her Majesty's coronation day
- David Cameron pays tribute to 'extraordinary' British monarch
- 63 years in photos
- Britain's longest-serving monarch by the numbers
The flotilla has got under way along the River Thames. Tower Bridge was raised to mark its beginning as boats make their way to the Houses of Parliament.
Liberal Democrat leader Tim Farron says the Queen has reigned with "humility and service" not by claiming "the grandeur of office". He finishes his speech with "long live the Queen".
Acting Labour leader Harriet Harman says how the Queen has gone from "sending telegrams to sending tweets" and has offered "the reassurance of continuity".
She quips that the Queen "rules over more than 140 million people. That is a huge number and almost as many as the Labour Party's registered members".
David Cameron is in the House of Commons addressing MPs on the Queen's reign. He says she is a "golden thread" that has run through three post-war generations and she "never falters" when performing duties she enjoys - like attending the Highland Games - or ones she might not, like "spending New Year's Eve in the Millennium Dome". The Queen spent December 1999 at the Dome alongside then prime minister Tony Blair.
THE QUEEN HAS ARRIVED! Along with the Duke of Edinburgh, the Queen arrived at Waverley to cheering crowds waving Union Jack flags. She passed the Royal Company of Archers before boarding the Union of South African steam locomotive for Tweedbank.
Bad weather in Balmoral means the Queen and the Duke of Edinburgh will be arrive at Waverley station 40 minutes later than scheduled.
The inclement weather probably means the monarch will boast one of her trademark hats. But which one will she plump for? This gallery of sartorial elegance might provide the answer...
The steam locomotive Union of South Africa has arrived at Waverley station before departing with Queen Elizabeth and Prince Philip, Duke of Edinburgh. Accompanying the couple will be Scotland's First Minister Nicola Sturgeon. The Queen will officially open the new Scottish Border's Railway, which runs from the capital to Tweedbank.