Dozens of Pakistani lawmakers rumbled through the streets of Islamabad on Thursday with one voice: Death to the blasphemers. Death to the blasphemers. Death to the blasphemers.

The “blasphemers” in this case were the Charlie Hebdo cartoonists who recently published a fresh depiction of the prophet Muhammad on their weekly newspaper’s cover in remembrance of the journalists who were killed in last week’s terrorist attack. “Making blasphemy cartoon of Prophet is the worst act of terrorism,” declared a photographed banner at the rally. “THE SKETCH MAKERS MUST BE HANGED IMMEDIATELY.”

It’s so commonly reported that Islam forbids Muhammad’s portraiture that it seems almost a waste of space to repeat it. After all, isn’t that why some Muslims were so outraged in 2006 when the Danish daily Jyllands-Posten depicted Muhammad in an unflattering light? Isn’t that why the Metropolitan Museum of Art pulled three paintings of the prophet? Isn’t that why the TV show South Park had to censor all mentions of Muhammad in a 2010 episode?  “Islam forbids images of Muhammad,” CNN boomed in a headline last week.

But the reality is substantially more complicated. The Koran, in fact, does not directly forbid the portrayal of Muhammad. And the second most important Islamic text, the Hadith, “presents us with an ambiguous picture at best,” wrote Christine Gruber of the University of Michigan. “At turns we read of artists who dared to breathe life into their figures and, at others, of pillows ornamented with figural imagery.” The most explicit fatwa banning the portrayal of Muhammad, she notes, isn’t tucked into some ancient text. It arrived in 2001. And its creator was the Taliban. The ban is a very modern construct.

Still, no one disputes its pervasiveness, nor its emotive underpinnings. To reiterate, Pakistani men on Thursday proclaimed that the worst act of terrorism was drawing Muhammad — a crime punishable by violent death. What explains this sentiment? Where did it come from?

To answer that question, one must travel back hundreds of years when the depiction of Muhammad in artwork was not all that uncommon. In non-Arab regions, researchers have unearthed a panoply of remarkable and detailed portraits of Muhammad that date before the 16th century. In one, a Persian image of Muhammad, clad in a white turban and bearded, preaches his final sermon. In another, a young Muhammad, hair parted into two ponytails, stands amid a throng of monks. One more shows Muhammad settling a dispute by placing a black stone into the center of a rug.

But such drawings were far rarer in the Arabian Peninsula, “where verbal reality eclipsed the reality of the visual image,” wrote Ali Aijdan in the Proceedings of the 11th International Congress of Turkish Art. He argued that there was a wide divide between Arab Muslim cultures and non-Arab Muslim cultures on how to handle artwork, which eventually led to the contemporary disappearance of Muhammad.

“An important element in Islamic aesthetics is the role played by Arabic language,” Ali wrote. “Among Arabic-speaking people, the need for illustrative pictorial art to accompany historical, religious, or literary works was rarely felt. For example, although the description of the Prophet is quite explicit in the Arabic annals, there is not a single picture painted by an Arab that portrays him. On the other hand, among the Turks, the Persians and the Indians, whose artistic heritage had been rich in pictorial images and whose language is other than Arabic, the Prophet was actually portrayed.”

Along the way, something changed in non-Arab drawings of Muhammad. He still appeared in paintings. But his features weren’t shown. Rather, they were covered with white linen or cloth, his form enshrouded by golden flame. (This depiction has carried over into modernity; in 2008, the Iranian government commissioned a five-story mural showing Tehran in such fashion.) Those pictures, however, soon disappeared as well. “As far as we know, the Prophet was never depicted with an open face since the 16th century,” Ali wrote.

Gruber, in an interview with the BBC, said the modern objection to images of Muhammad may have been a reaction to colonization by Christians, with their images of Jesus and the crucifix. It was during the colonial era that pictures showing Muhammad began to vanish, replaced by an aversion to his image.

“To a large extent, this divide is rooted in real-world grievances rather than theology: a sensitivity caused by many Muslims’ perceptions that they are under attack by the West,” wrote the Wall Street Journal’s Yaroslav Trofimov. “And that their societies are in seminal economic and cultural decline that started with European colonization centuries ago.”

But even in modern times, Muhammad’s image continued to appear in Muslim nations, including Iran, where until recently, the Guardian reported, carpets showing his image as well as postcards were openly sold.

Of course, many who have no religious objection to images of Muhammad per se deeply resent cartoonish images that ridicule the prophet or make fun of Islam. As Pope Francis told reporters this week in commenting on the Charlie Hebdo portrayals, “you cannot make fun of the faith of others.”

En route to the Philippines, Pope Francis condemned last week's deadly attacks in Paris, but said it's wrong to insult religious beliefs. (Reuters)