We still don’t know the whereabouts of Alexander the Great’s tomb, but the mystery of how the Greek leader and conqueror died may be closer to being solved. A new theory spotted by Smithsonian suggests that Alexander may have been paralyzed—and not actually deceased—at the time he was declared dead in 323 B.C.E.

His untimely demise at the age of 32 has been the subject of debate. Some scholars say he died of a biliary tract disease after going on a booze-fueled bender with friends, while others theorize that he was poisoned. Medical historians have no choice but to rely on secondhand accounts of Alexander’s symptoms, such as Plutarch’s biography of Alexander, written hundreds of years after his death. However, Plutarch's account provided a seemingly important clue that has largely been ignored in past theories: It took six days for Alexander’s body to decay.

Dr. Katherine Hall, a clinician and professor of medicine at New Zealand’s University of Otago, writes in The Ancient History Bulletin that paralysis might explain why his corpse stayed so remarkably fresh. “The ancient Greeks thought that this proved that Alexander was a god; this article is the first to provide a real-world answer,” she said in a statement.

Specifically, Hall suggests Alexander may have suffered from a disorder called Guillain-Barré Syndrome (GBS), in which the immune system starts to attack nerve cells. The neurological disorder can be caused by a Campylobacter pylori infection, which was common at that time.

Alexander’s symptoms included fever, abdominal pain, and paralysis that progressed to the point where he could no longer lift his head. However, throughout the whole ordeal, he remained conscious and clear-headed. Hall says the paralysis may have lowered his body’s need for oxygen, resulting in dilated pupils and a low body temperature. Doctors at that time may have thought he was dead because they checked for breathing, not a pulse.

“I wanted to stimulate new debate and discussion and possibly rewrite the history books by arguing Alexander’s real death was six days later than previously accepted,” Hall said. “His death may be the most famous case of pseudothanatos, or false diagnosis of death, ever recorded.”

Still, it’s impossible to know for sure. Determining the cause of death of famous historical figures is a fairly popular pastime among medical professionals, but without clinical evidence their findings generally can't be considered conclusive. There’s even an annual event at the University of Maryland School of Medicine called the Historical Clinicopathological Conference, where attendees use the evidence on record to explain what felled Charles Darwin, Edgar Allan Poe, and some long-dead leaders. As for their conclusions about Darwin and Poe, a parasitic illness called Chagas disease and rabies, respectively, supposedly did them in.

[h/t Smithsonian]