Henry VIII ruled for 37 years, a period that saw him establish England on the world stage. But his reign was also marked by tumult, including his break with the Catholic Church, drastic changes to English religious and political life, profligate spending and an exceedingly troubled personal life that saw several wives cast aside. But how much of this can be chalked up to the injuries and ill-health Henry suffered throughout his life and does medicine help us solve the riddle of this troubled king?

Young Henry was the epitome of a 'Renaissance Prince'

Henry was not born to be king. The second son of Henry VII and his wife Elizabeth, Henry spent his earliest years surrounded by his mother and her ladies-in-waiting, in contrast to his older brother Arthur, who as heir was raised in his own household. Henry received a top-notch education and was a talented student. He composed music and poetry, mastered a number of languages and studied theology, with an eye on possibly joining the church, a common role for second sons from prominent families.

He was also considered exceedingly good looking for his era, with foreign ambassadors praising his physical attributes. More than six feet tall as an adult, he was an avid athlete with a sportsman’s body, excelling at everything from dancing and tennis to jousting and hunting. He was also, by all accounts, a cheerful lad — an image hard to reconcile with the tyrant to come.

Henry’s obvious health and vitality were at stark odds with his dour and ruthless father, whom a later historian would aptly dub the “Winter King.” By contrast, after Henry assumed the throne, his subjects bestowed a far more flattering nickname, as “Buff King Hal.”

READ MORE: 7 Surprising Facts About King Henry VIII

He was terrified of catching diseases of the day

Henry’s life was forever changed when he was 10. Arthur, five years older and of a more delicate constitution, died of an unknown ailment just six months after marrying Spanish princess Catherine of Aragon. Henry assumed the role of Prince of Wales, became king less than eight years later and soon married his brother’s widow.

The threat of illness and possible death plagued Henry. And he had every right to be fearful, as outbreaks of typhus, dysentery, influenza and the dreaded, mysterious “seating sickness” were common. Henry survived an early bout of smallpox and may have suffered recurrent bouts of malaria, forcing him to become even more diligent. Doctors and officials traveled ahead of his annual royal progresses around England to ensure nobody in his path was ill, and those suffering from communicable diseases were forced to leave his court after becoming sick.

Henry also had a lifelong fascination with medicine, tinkering to make his own recuperative concoctions. He founded the Royal College of Physicians in 1518, formed a company of “barber-surgeons,” made improvements to England’s public health services and even stewarded through legislation regulating the licensing of doctors and medical practitioners.

Unhealed injuries may have caused his later health problems

As careful as young Henry was at maintaining his health, his ego and bravado may have been his undoing. Jousting was considered the most masculine sport of the medieval world, and Henry thrilled to prove his manhood on the “lists.” In 1524, 32-year-old Henry was seriously wounded when an opponent’s lance hit him just above the right eye. He would suffer severe migraines for the rest of his life.

An even more dangerous accident occurred 12 years later when he was 44. Henry, wearing full body armor, was thrown from his horse during a tournament. The horse fell on him, knocking him unconscious for nearly two hours (and initially leading many to believe he had died). Henry never fully recovered from his injuries, and modern scientists and historians have surmised that the accidents also caused irreversible brain trauma, which may explain the bouts of bad temper and violent outbursts that became increasingly frequent and severe as the king aged.

Henry’s biology may have been the cause of his reproductive problems

Henry famously wed six times, in a constant search for a male heir to ensure the Tudor dynasty (of which he was only the second king) would survive. He divorced his first wife (and the Roman Catholic Church), after nearly 20 years because Catherine had just one surviving child, a daughter. Second wife Anne Boleyn was dispensed with after a daughter and several miscarriages. Third wife Jane Seymour did give birth to a son but died before she could produce the desired “spare” second son.

Henry railed against his wives’ fertility woes, blaming seemingly everyone but himself for his lack of sons. But a 2011 study indicates Henry’s own blood may have been at fault. Researchers, including bioarcheologists, announced that they believe Henry had McLeod’s syndrome and was Kell positive, a rare blood grouping that affects less than 10 percent of the world’s population.

If Henry were Kell positive and his wives Kell negative, the wives’ body would have eventually built up anti-bodies that fatally attacked her fetus. First pregnancies (such as Anne’s with Elizabeth and Jane’s with Edward) would have been unaffected, while subsequent ones would have been almost certain not to come to full term. According to the study, this could help explain the repeated late-term miscarriages suffered by both Catherine and Anne.

He weighed nearly 400 pounds when he died

Historians and medical experts have also speculated that Henry suffered from any number of other issues, including Cushing’s syndrome, diabetes and syphilis.

Whatever was ailing the king, it steadily worsened. Painful, pus-filled, suppurating ulcers on his legs, which were probably initially caused by his jousting and exacerbated by his vain insistence on wearing constrictive leg garters, became almost unbearable, despite repeated treatments. He suffered from sexual dysfunction, a blow to his supposed virility. His vision grew worse, his headaches increased and his mood swings took a deadly turn, as those who seemed to cross the paranoid, unstable king were caught in his vindictive crosshairs.

His inability to exercise led to massive weight gain, which can be tracked by his evolving body armor, which shows his waist growing from 32 to 52 inches. And yet, he continued his notorious eating, perhaps swallowing his pain and misery along with food and ale. He developed gout and eventually had to be lifted on to his horse and carried around on a chair. He finally died in January 1547, aged 55.

And the son Henry had so desperately wanted? Young Edward VI became king at age nine, and reigned for just six years, dying at 15 from what was likely tuberculosis. He was succeeded by his two half-sisters, Mary and Elizabeth, whose own failures to produce heirs led to the end of the Tudor dynasty.