On the day she becomes the longest-serving British monarch in history, Queen Elizabeth II thanked her well wishers for their "kindness" at the opening of a new rail line in Scotland. (Reuters)

During Queen Victoria’s reign, Britain was an economic powerhouse and its railway lines rapidly spread across the nation like arteries.

So perhaps it was only fitting that Queen Elizabeth II marked the milestone of becoming Britain’s longest-reigning monarch, steamrolling past the record of 63 years and 216 days set by her great-great-grandmother, by officially opening a railway line.

“Inevitably a long life can pass by many milestones. My own is no exception. But I thank you all, at home and overseas, for your touching messages of great kindness,” the 89-year-old queen said to a throng of well-wishers here Wednesday.

The reluctant record-breaker then returned to “the business in hand” and unveiled a plaque opening the train line in little Tweedbank in the Scottish Borders.

The well-wishers who waited more than three hours in chilly weather to see the world’s most famous royal — dressed in a striking turquoise dress — did not seem disappointed.

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“My kids know who the queen is from telly, but they have never seen anything like this,” said Misty Crew, a 30-year-old beautician whose 2-year-old daughter wore a toy crown with pink jewels.

Not that her majesty wanted a fuss. Queen Elizabeth II may have clocked more throne time than any other king or queen in the 1,000 years of the British monarchy, but palace aides have long insisted that she wanted the occasion to pass without fanfare.

“She really takes it in her stride,” said Dickie Arbiter, the queen’s former press secretary. “She was asked to do a job of work, and she will do a job of work until she dies. The fact that she’s exceeding Victoria’s reign, it’s just the way it’s fallen into place.”

Said a spokesman for Buckingham Palace: “The queen has said from the start Wednesday is business as usual.”

British lawmakers apparently did not get that memo. Prime Minister David Cameron, among the many who gave thanks in Parliament, called Elizabeth’s reign a “golden thread running through three post-war generations.” Other politicians in Commonwealth countries — a club of nations of which the queen is the nominal head — also paid their tributes.

There’s no questioning the House of Windsor’s broad support; two-thirds of respondents in a recent poll said they think that Britain should continue to have a monarchy.

To be sure, there are republican voices — support hovers around 20 percent in the polls — but they are less boisterous than they were during Queen Victoria’s reign at the turn of the 20th century.

Jeremy Corbyn, the front-runner in the Labor Party leadership race, is a staunch republican, although he has said that abolishing the monarchy would not be a priority if he becomes leader.

“Politicians posture in opposition, but when they come to power they are all over her like a rash,” Arbiter said.

The queen will be 90 in April and has cut back on travel, but she still keeps an exhaustive work schedule — last year, she carried out more than 300 engagements. A recent poll by Opinium Research found that 71 percent of surveyed Britons were satisfied with how she conducts her duties.

It has not always been smooth sailing. The queen famously referred to 1992 as her “annus horribilis” — Prince Charles and Diana separated that year, and a fire badly damaged Windsor Castle.

Support for the monarchy took a major knock in the aftermath of Diana’s death in a car crash in 1997, when the royal family’s response was criticized as being cold and callous.

But with relatively few blips, the queen has steered the monarchy with a steady hand since being crowned when she was 25. It was 1952, and Britain was a very different place than it is today. The nation was reeling from World War II, with rationing of food and clothing still in effect. And while much has changed over the past 63 years, the monarch has remained the same, reigning calmly above the fray.

Very calmly.

David Starkey, a British historian, caused a stir recently when he said that the queen had “done and said nothing that anybody will remember” and that she would not lend her name to an age.

Writing in Radio Times magazine, he added that she had “perfected the art of talking without saying anything.”

That is precisely what some Britons say they admire about her: She is an uncontroversial figure and, like the weather or wallpaper, she has just always been there.

“She is dull. She’s been around so long. She’s in the background all the time. That’s what we like about her,” said John Hindmarch, 68, a retired banker who on a recent day was snapping pictures of the marching guardsmen outside Buckingham Palace.

His sister Sandra, 62, was skeptical that the queen was an image of placidity behind closed doors. “She’s completely different at home, apparently,” she said, adding that “she’s just always been really professional about everything. ”

Commentators have said that the lack of celebratory mood on the part of the royals is colored by the fact that the milestone is tied up with the deaths of Queen Victoria and the queen’s beloved father, George VI.

And as royal occasions go, this did not inhabit the same stratosphere as the queen’s Diamond Jubilee or the Duke and Duchess of Cambridge’s royal wedding. But passing the moment unmarked was clearly not an option for many here. In London, a flotilla of boats traveled the Thames in honor of the queen, and the BT Tower carried the scrolling message “Long May She Reign.”

Acting Labor leader Harriet Harman told Parliament that “it’s entirely characteristic of her that she has let it be known that she doesn’t want there to be a fuss made about today, but we are making a fuss, and deservedly so.”

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