When British archaeologist Howard Carter opened a sarcophagus in Egypt’s Valley of the Kings for the first time on February 16, 1923, he stoked intrigue and mystery over an ancient Egyptian boy king. Who was King Tutankhamun, the occupant of the burial chamber who ruled 3,300 years ago, and how did he die at the age of 19?

Carter didn’t have an answer back then, but modern forensic and medical technologies have uncovered details that provide clues as to what may have plagued King Tut before his death. DNA tests and computerized tomography (CT) exams showed he suffered from malaria, a fractured lower leg and congenital deformities associated with inbreeding that was common among Egyptian royalty.

Swiss mummy expert Frank Rühli noted in 2014 that in the years since the discovery of King Tut’s tomb, many researchers, academics and amateur Egyptologists have come up with theories about what ultimately killed the boy king. In each case, however, the evidence was interesting but not compelling.

The CT scans of Tutankhamun found a cleft palate and fairly long head, as well as a curved spine and fusion of the upper vertebrae, which are conditions associated with Marfan’s syndrome. But DNA tests in 2010 proved negative for that diagnosis.

In 2014, producers of a BBC television documentary postulated that Tut died in chariot crash that broke his legs and pelvis, and resulted in an infection and perhaps death by blood poisoning. Supporters of this theory note that Tut was depicted riding on chariots and also suffered from a deformed left foot, making it possible that he fell and broke his leg.

While that theory sounded like a good story, there were no records that such an incident occurred. In fact, one of the Egyptologists involved in that British television program still has doubts about what happened.

“We cannot at present know how Tutankhamun died,” says Christopher Naunton, an Egyptologist and former head of the Egypt Exploration Society. Naunton says the BBC documentary started from the premise that the mummy showed evidence of the king having suffered severe trauma to his left torso and side. The filmmakers commissioned research that showed that this kind of injury could have been caused by the impact of a chariot wheel, but not by a fall from a chariot.

What remains unclear, Naunton says, is whether the skeletal damage occurred during the king’s life or long after his death, as a result of the handling of the mummy after the discovery of the tomb by Howard Carter.

“It’s quite possible what ultimately killed him has left no trace,” Naunton says.

One obstacle to reconstructing Tut’s life is the condition of his mummy after its discovery in 1923. Carter first examined the remains in 1926 and then returned the mummy to the outer burial chamber where it remained until 2007. During that time, some of the necklaces and jewels buried with Tut were removed, perhaps fracturing the fragile remains.

“Those of us who have anything to do with mummies know the degree that post mortem changes with the effects of mummification itself and along with what may have happened are really difficult to factor in and create a believable narrative,” says Betsy M. Bryan, professor of near Eastern studies at Johns Hopkins University, who has worked for decades researching ancient Egypt. Bryan says she believes that new forensic technologies will ultimately improve enough to determine what happened. “I have great faith in science,” she says.

Rühli, the Swiss mummy expert at the University of Zurich, argues what’s needed is not more science, but perhaps another inspection of Tut’s remains. “New technology is not necessary,” he says. “However, what would be most helpful is a profound eye-only (with a magnifying glass) investigation of the suggested trauma sites (feet, knee, face) on the mummy itself.”

Not only is King Tut’s death a mystery, there are also gaps in the story of his life. Tutankhamun was the son of a controversial Egyptian king, Akhenaten, who decreed that Egypt would worship a single god, Aten, instead of many, and moved its capital from Thebes to Amarna. Politically, Egypt grew weak during Akhenaten’s 13-year reign, according to David P. Silverman, professor of Egyptology at the University of Pennsylvania, who was curator of the first King Tut exhibit in 1978 at the Field Museum of Chicago.

Silverman says that Tut restored the old gods and their temples, erasing the changes brought by his heretical father and returning the kingdom to stability. The rulers who followed erased written representations of both father and son from Egypt’s important list of kings, he explains, and both tombs were considered lost until their discovery in the early 20 century.

“They specifically tried to take memory of the entire family away by not including them in later lists of kings. It’s as if these people didn’t exist,” Silverman says.

While records of his life were erased, in death, King Tut became ancient Egypt’s most famous pharaoh. Carter hinted at that future fascination when he first entered the pharaoh’s tomb in the Valley of the Kings. Asked by a colleague on the outside if he saw anything, Carter replied, “Yes, wonderful things.”