In 1509, King Henry VII passed away. Ascending to the throne was his second son, an 18-year-old prince who was crowned King Henry VIII. King Henry VIII’s reign became one of the best known in English history. Famous for having six wives, he broke with the Roman papacy and established the Church of England so he could receive an annulment from his first wife Catherine of Aragon, who was his late brother’s widow. He also was known as the “father of the Royal Navy,” growing the fleet from five royal warships to around 50 by the time of his death in 1547.

Later in life, Henry VIII was also known for his ill-temper, and physical heft, among other physical and psychological ailments. Historians note his behavior drastically changed in 1536. As British historian Suzannah Lipscomb said, he moved from being the “glorious, and fun young monarch of the 1510s and 1520s, into an overweight, suspicious, ruthless tyrant.”   

According to research from a Yale Univ. cognitive neurologist, Henry VIII’s explosive behavior may’ve resulted from repeated traumatic brain injuries, much like the injuries experienced by players in the National Football League.

Researchers pored through Henry’s letters and other historical documents to gain a comprehensive understanding of his recorded medical history and the events in his life, which may have led to his later behavior.

The researchers cited three head injuries Henry suffered. In 1524, while jousting, Henry’s helmet was penetrated by a lance in a tournament. This was followed by an incident where he fell into a brook head-first while trying to cross it with a pole. That fall, a year later, knocked him out. But the coup de gras likely occurred in January 1536. During a jousting match, a horse hell on the monarch, knocking him out for two hours.

After the incident, historians maintain that he became impulsive, forgetful, and prone to rage.

Study senior author Arash Salardini, who is co-director of the Yale Memory Clinic, believes traumatic brain injury can also explain Henry’s metabolic syndrome and reported impotence, as side effects of traumatic brain injury include growth hormone deficiency and hypogonadism.  

However, Tudor historian Tracy Borman is not convinced. Writing in History Extra, Borman lambasts the study, writing “Historians have long speculated that there may be a link between Henry’s personalist change and the injuries he suffered in the tournament arena. The memory loss that the Yale team ascribes to Henry could more accurately apply to the media who have been busy shouting about this exciting ‘new’ discovery.”

Instead, Borman credits Henry’s foul mood to nasty leg injury that turned ulcerous.

Salardini responded, “As a physician, the idea that the leg pain described all (Henry’s) symptoms does not come close to being the second-most-likely diagnosis.”