The Bayeux tapestry is a glorious 70-meter-long creation that has survived for nine centuries. This historical artifact, which shows the Norman invasion of England led by William the Conqueror, has been extensively analyzed by academics. But until now, one crucial detail has been ignored: The penises.

Among the 626 humans and 190 horses on the tapestry, there are 93 visible penises, according to a thorough count by George Garnett, medieval history professor at the University of Oxford. Of these, 88 are equine penises, and five belong to humans.

Garnett believes that the sheer number of penises is a sign that the embroiderers were male. “This is just the sort of thing which will be familiar to anyone who has spent any time in a boys’ school, but seems unlikely to have been the product of a female mind,” he wrote in BBC history magazine website, Historyextra. “I am making large assumptions about continuity in male and female psyches over a millennium, but in this instance I do so with few qualms. Does the profusion of penises reveal anything more than a male adolescent mentality on the part of the tapestry’s designer?”

Though Garnett is confident, another scholar notes that a profusion of penises isn’t necessarily a sign of schoolboy obsessions. “That’s so speculative,” says classics academic Andrew Lear, who has previously taught at Harvard, Columbia and NYU and currently organizes art history tours focused on gay history. “Something that looks immature to us may not have been immature in other time periods.”

Regardless of who created the penises, Garnett suggests that their presence can help us interpret the tapestry. The two protagonists shown, Anglo-Saxon King Harold and William the Conqueror of Normandy, have horses with particularly large penises, notes Garnett. And William’s horse’s penis is by far the largest.

“The clear implications are that the virility of the two leading protagonists is reflected in that of their respective mounts, and that William was in this respect much the more impressive of the two,” he writes. “Duke William had to be the outstanding individual in every respect, including his horse’s penis.”

The tapestry thus seems to link penis size with both manliness and strength: It is a medieval nod to the modern-day notion that the bigger the penis, the more mighty the man.

This may seem like an age-old, universal theory—much like the idea that adolescent boys are obsessed with penises. But the link between penis size and virility is far from a common theme in art history.

“Normally in Greek art a large penis is a sign of being lazy and lacking appropriate self control. Drunk people have large penises,” says Lear. Small penises were the ideal in ancient Greece, as a reflection of the idea that the perfect man was ruled by reason rather than lusty instincts.

Meanwhile, Japanese erotic art, or shunga, which were especially popular from the 17th to 19th centuries, show extremely large penises—but there’s no hint or commentary about what penis size is meant to suggest about the man. “There’s no contrast in Japanese culture between big and small penises, it’s just that men’s penises are huge,” says Lear. As Japan was closed to most international interactions until the mid-19th century, the country was largely uninfluenced by Christian notions of modesty; big penises, then, were nothing to boast about, but nor were they seen as embarrassing.

The cultural associations around sex shift dramatically over time and cultures. And certainly medieval ideas about sex and sexuality were, in many respects, markedly different from today. (One medieval theologian ranked sexual positions in the order of least to most sinful, with missionary as the most morally acceptable, followed by side-by-side, seated, standing and, finally, a tergo, or from behind.)

And yet the theory that a large penis is linked with manliness and military victory seems to have been present in medieval times. Much like the Bayeux Tapestry, this assumption has survived, largely intact, for 950 years.