Business as usual as Queen enters the royal record books
The Queen is now the longest reigning monarch in British history.
She has surpassed her great-great-grandmother Queen Victoria's record on the throne and has reigned for more than her 23,226 days, 16 hours and 30 minutes.
The monarch, however, remains modest and matter of fact about the achievement.
Although she thanked the nation for the kind messages as she opened the Borders Railway in Tweedbank on the landmark day, she admitted that the milestone was "not one to which I have ever aspired".
She added: "Inevitably a long life can pass by many milestones. My own is no exception. But I thank you all and the many others at home and overseas for your touching messages of great kindness."
From the outside, the Queen's trip to the Scottish Borders had all the trappings of a typical working day at the office.
It featured the official opening of a major transport project, plaque unveilings, flag-waving schoolchildren and dignitaries nervously waiting in line to meet their Head of State. She has been criticised by some for never expressing an opinion, never doing anything to stand out in comparison with her forebears and so cannot be considered a "great" Queen.
Her public style is more subtle. She is an unobtrusive host, who listens, puts people at ease and accepts their good wishes.
Underlying it all is the momentous fact that yesterday she became the longest reigning monarch in British history.
By working as normal, she demonstrated how she has dedicated herself to the role of Queen, and is not distracted by moments for the history books.
On the steam train that took her and Duke of Edinburgh from Edinburgh to Tweedbank, she appeared at ease, sitting by the window watching the countryside go by.
Back at Balmoral last night, the Duke and Duchess of Cambridge joined the Queen for dinner, although it is understood the gathering was not to mark the longest reign.
The rest of the royals carried on with their scheduled engagements, with the Duchess of Cornwall describing the milestone as "marvellous" on a tour of the studios at breakfast TV show Good Morning.
Heir to the throne and future King the Prince of Wales was filming a Prince's Trust documentary with Ant and Dec.
The Duke of York praised his mother's consistency and leadership.
But he described the day as a "normal run-of-the-mill sort of date. It's just one day in her reign".
Although celebrations were much more low-key than any of the jubilees, a flotilla of boats processed down the River Thames led by the royal rowbarge Gloriana.
HMS Belfast sounded a four-gun salute and the Massey Shaw fireboat shot jets of water across the river, while Tower Bridge was lifted in recognition of the sovereign.
And Westminster Abbey and other churches and cathedrals rang their bells in the monarch's honour.