Feared, loved, and reviled, the cornerstone of Rupert Murdoch's international media empire celebrated 40 years under his control this past week. The best known of Britain's tabloids or "red tops" mixes a cocktail of blaring headlines, celebrity gossip, sports and hard news exclusives that have often brought it in for criticism.
Its best riposte? That it has remained, through thick and thin, the country's largest circulation newspaper.
The paper was a struggling broadsheet when Mr. Murdoch bought it in 1969, and quickly converted it to a popular and populist tabloid that unlike its tabloid cousins in the US wields major political clout.
The Sun has produced some of British journalism's iconic moments – from celebrated scoops to its infamous "Gotcha" headline after the British navy sunk an Argentine warship during the 1982 Falklands War with the loss of 323 lives.
While the paper is grappling with the crisis faced by the entire newspaper industry, it remains a potent player in British politics – though perhaps not as potent as it once was.
Its continued ability to set the political agenda was demonstrated earlier this month when Prime Minister Gordon Brown apologized to the mother of a British solider killed in Afghanistan after The Sun revealed her anger that a condolence note sent by Mr. Brown was littered with spelling errors.
But for many, there was a hint of the paper's loss of influence in the backlash against its publication of a transcript of a phone call Mr Brown made to the mother, which she apparently taped.
Elsewhere, commentators on the tabloid's 40th anniversary charged it with helping to "coarsen" British society, not least through its casual depiction of semi-naked women every day on page three.
Roy Greenslade, a sub-editor 40 years ago on the first issue of the tabloid, says that while he appreciates The Sun's role as a sensationalist tabloid newspaper "engaging with and entertaining its readers," he regards it as "a reactionary political force" often guilty of "casual cruelty."
"Because it's now 40 years old, it has changed and society has changed," says Mr. Greenslade, now a professor of journalism whose career included a stint as The Sun's assistant editor from 1981-86 and as editor of its more left-wing rival, The Daily Mirror, from 1990-91.
He divides the Sun's history into two periods. The "saucy and irreverent" era between 1969 and 1981 and a more aggressive period from 1981 onwards when it "moved from being saucy to being a lot more sleazy" under the editorship of Kelvin MacKenzie. Mr. MacKenzie is a British journalist with near legendary status in media circles, as much for his news sense as for his infamous foul-mouthed management style.
"I think it has hovered ever since between those two stages – sometimes saucy and sometimes sleazy," added Greenslade. "But standards and tastes have changed, so people are much more accepting of sleazy material than they once were."
He also says that another much-repeated suggestion, that The Sun's support is worth as much as a two-percent swing to the party it backs during any general election, is an exaggeration.
Nevertheless, one of the landmark political stories of this year was The Sun's withdrawal of support from the Labour Party, which earned the tabloid's historic backing weeks before Tony Blair's landslide general election victory in 1997.
While the paper is now back in the Conservative fold, providing favorable coverage to Tory leader David Cameron, many have suspicions about the depths of this support.
Writing in The Independent, media commentator Stephen Glover said that Murdoch still genuinely likes and admires the beleaguered Brown, adding: "Their roots intertwine because of their Scottish and Presbyterian backgrounds, as well as their shared belief in the virtues of work... it is also true that Rupert Murdoch does not much like David Cameron, who suffers in his estimation from being posh, young and English."
Glover suggested that the roots of The Sun's recent political shift lie with Rupert Murdoch's son, James, who oversees his father's British media holdings and has been described as an admirer of Cameron.
Whether the tabloid's support actually translates into a two-percent boost or not, one of the paper's most senior figures of recent times still maintains that its political weight is "phenomenal."
"Political leaders strive for positive coverage in The Sun because its huge army of readers all have votes and opinions which matter," says George Pascoe-Watson, who spent 22 years at the paper, working his way up from a junior reporter to political editor before moving into public relations this year.
He links the overall secret of its success to a knack of tuning into the thinking of vast swathes of the British population on a range of issues and a deployment of humour "to deflate the egos of the establishment."
"The Sun understands the complex issues of modern life and has an opinion on everything. Crucially, it presents those views with crystal clarity," he says. "Everything The Sun does is aimed at its readers' interests. Sun readers, and there are around 10 million every day, feel they are part of a Sun "family" where the newspaper is fighting in their corner."