There is no question that master artist Caravaggio lived a complicated life. Artistically, he was a genius who is best known for developing the technique known as “chiaroscuro,” which defines the intense detail of light and dark in his paintings. But his personal life was haunted by demons. His violent temper once led him to assault a waiter over the way his artichokes were seasoned. His lack of control led him to kill a man during a swordfight. His lovers all ended up hating him. His friends often beat him to a pulp out of frustration. His disregard for the law put him in prisons across Italy and Malta.

The artist, born Michelangelo Merisi, is thought to have died July 18, 1609, but despite many often-contradictory theories, no one has ever been able to prove just how he died until now. His last bout with the law, in 1606, resulted in a murder conviction for which a bounty was put on his head—literally. Whoever killed him was to bring his severed head to Rome for a reward. But his head was never brought to the Rome courts, and instead for centuries he was thought to have perished on an unknown Tuscan beach, either succumbing to a fever from an infection he suffered in a brawl or from malaria, which was rampant at that time. Then, in 2010, bones thought to be his were found in a seaside church grave in Porto Ercole on the Tuscan coast. Analysis of the remains led some scholars to pin his death to lead poisoning from his oil paints or possibly to sunstroke, which likely turned fatal thanks to a bout of syphilis.

But now the latest theory on Caravaggio’s death seems the most likely. Professor Vincenzo Pacelli of Naples says it was the Knights of Malta who killed the rogue painter in a murder that the Catholic Church endorsed and then hid for centuries. Pacelli has spent years researching the inconsistencies of Caravaggio’s death in the Italian state archives. Three years ago he got access to the Vatican’s secret archives, which, he says, provided the missing link. “Caravaggio did not die in Porto Ercole of an illness,” he says. “He was the victim of a violent murder and dumped in the sea near Palo Laziale. His assassination was ordered by the state and blessed by the Holy See.”

Pacelli, who says his research unequivocally points to the Knights of Malta, a Catholic military order formed during the Crusades, outlines the theory in footnoted detail in a new book released in Italy this week, Caravaggio: Between Art and Science. During his time in Malta, Caravaggio was briefly inducted into the powerful order, effectively becoming its artist until he was kicked out.

Noted art historian Andrew Graham-Dixon was the first to toy with the Knights of Malta–assassin theory publicly in his book Caravaggio: The Secret and the Profane. One of Caravaggio’s last acts of violence, the author writes, was an attack against Giovanni Rodomonte Roero, a senior knight with the order. Graham-Dixon uncovered the truth behind archives that had been obscured by the Knights of Malta order to clarify the legend. For centuries, scholars had thought that Caravaggio’s last crime was killing a noted Roman pimp Ranuccio Tomassoni, but it was an assault on the knight. Roero survived the brawl, and Caravaggio was sentenced to prison, from which he escaped under mysterious circumstances after only a month of incarceration.

Graham-Dixon writes that Roero then sought out Caravaggio and took his revenge on him one night in Naples outside the Osteria del Cerriglio, which was a well-known gay establishment at the time. The murder just a short time later may have been a vendetta on Roero’s behalf. And both Pacelli and Graham-Dixon agree that it was a convenient time for the church to see the last of Caravaggio’s work. At the time of his death, and despite his demons, Caravaggio was gaining a popular following, in part because of the way his masterpieces depicted Catholic Church doctrine with human emotion on the tortured souls and sinister saints, which was in stark contradiction to how the church wanted its divine words illustrated.

The church may have covered up Caravaggio’s death for centuries, but it certainly didn’t stifle his creative influence. The artist’s struggles were matched by his prolific talent, and his works are on display as masterpieces in many churches and museums, from Rome to Malta.