When attackers burst into the weekly meeting of Charlie Hebdo on Wednesday and unleashed fatal gunfire on 10 journalists, four of them the magazine’s rambunctious and irreverent cartoonists, they struck at the heart of a paper that had become a symbol of free speech in France.

Stéphane Charbonnier, the paper’s editor who went by the nickname Charb, Jean Cabut (Cabu), Georges Wolinski and Bernard Verlhac – all veteran cartoonists regarded as pillars of political satire in France – were among the 12 victims of the attack. The economics columnist Bernard Maris, a member of the Bank of France’s general council, was also killed. One cartoonist, Renald Luzier, known as Luz, managed to escape the carnage.

As many French journalists gathered in Paris to pay silent tribute to their dead colleagues, Plantu, the cartoonist of Le Monde, tweeted a drawing of a pen writing in red ink. “With all my heart,” it read, “with Charlie Hebdo.”

Dependably provocative and indiscriminately rude, the magazine had come to embody freedom of expression by targeting Islam with its politically incorrect brand of satire. Moments before the attack, a cartoon depicting Abu Bakr al-Baghdadi, the leader of Islamic State (Isis), was posted on its Twitter account. The magazine’s cover this week features Michel Houellebecq’s provocative new novel, Submission, which imagines France being ruled by a Muslim president.

In a tragic irony, Charbonnier’s last cartoon predicted his own death. The latest edition of the weekly shows a gun-toting Islamic terrorist saying: “Still no attacks in France? Wait – we’ve still got until the end of January to present our best wishes.”

Charbonnier maintained that there should be no taboos in French society, and condemnation made him all the more determined to court controversy. His publication responded to efforts at intimidation by being even more irreverent or outrageous, defying the constraints of religious sensitivity or political correctness.

In November 2011, the magazine’s offices were fire-bombed after it published a special edition, supposedly guest-edited by the prophet Muhammad and temporarily renamed “Charia Hebdo”. The cover was a cartoon of Muhammad threatening readers with “a hundred lashes if you don’t die laughing”.

The petrol bomb attack destroyed the Paris offices, the magazine’s website was hacked and staff including the editor were subjected to death threats. But that did not deter Charbonnier. Six days later, the magazine published a front page depicting a male Charlie Hebdo cartoonist passionately kissing a bearded Muslim man in front of the charred aftermath of the bombing. The headline was “L’Amour plus fort que la haine” – Love is stronger than hate.

Less than a year later, the magazine published more cartoons of Muhammad, including images of him naked and a cover showing him being pushed along in a wheelchair by an Orthodox Jew. The French government had appealed to the editors not to go ahead with publication, and when they went ahead anyway it shut down embassies, cultural centres and schools in 20 countries out of fear of reprisals.

Riot police were deployed to the Charlie Hebdo offices to protect it from direct attacks. The foreign minister, Laurent Fabius, publicly criticised the magazine’s actions, asking: “Is it really sensible or intelligent to pour fuel on the fire?” Gérard Biard, the editor-in-chief, rejected the criticism. “We’re a newspaper that respects French law,” he said. “Now, if there’s a law that is different in Kabul or Riyadh, we’re not going to bother ourselves with respecting it.”

In January 2013, Charlie Hebdo published a cartoon book, The Life of Muhammad, sparking another fierce debate over the freedom of expression in France. Its cover pictured a goofy-looking prophet leading a sweating camel through the desert. Charbonnier said the “biography” was “authorised by Islam since it was edited by Muslims”.

The magazine had first provoked international outrage in 2006, when it republished cartoons of Muhammad from Denmark’s Jyllands Posten. On Wednesday the Danish paper stepped up its own security in response to the Paris shootings.

While the attacks on Charlie Hebdo for its depiction of Muhammad and its consistently defiant response have put the focus on its attitude to Islam in particular, the magazine’s earlier history reflects a readiness to offend all religions and challenge all taboos.

In 1970 its precursor, Hara-Kiri Hebdo, was banned for publishing a spoof of the reverent French coverage of the death of the former president Charles de Gaulle. To sidestep the ban, the editors renamed the magazine, choosing Charlie Hebdo because there was a monthly comic book in existence called Charlie Mensuel (named in turn after Charlie Brown) and as an irreverent reference to the recently deceased father of the French fifth republic.

The magazine folded in 1981 because of a lack of sales but relaunched in 1992 in its present form.