During a jousting tournament at Greenwich, King Henry VIII was involved in a catastrophic accident that would have lasting effects on both his physical health and his reign. The tournament was a high-profile event with multiple knights, reflecting the king's enduring passion for chivalry and martial prowess. On that fateful day, while competing, Henry's horse collided with another knight's horse, causing him to fall, with the full weight of his body impacting the ground. The king was immediately knocked unconscious, prompting immediate concern among those present about his condition.

Henry was ultimately revived and treated, but reports indicate that he sustained significant injuries, including trauma to the head. This incident marked a turning point in Henry's life, as it has been retrospectively analyzed by historians as potentially influencing his subsequent erratic decisions and shifting character traits. Following the accident, observers noted changes in his temperament, which may have stemmed from both physical and psychological effects of the injury.

In the years following the accident, Henry would show signs of paranoia and aggression that compounding the political tensions of his reign, which included issues surrounding succession and the fates of his marriages. Additionally, there are historical accounts suggesting that the jousting accident may have compromised his physical vitality, leading to speculations about his impotence, particularly in relation to his marriage with Catherine Parr, his final wife. This perception of physical decline also intertwined with how he ruled, leading to a dangerous blend of power and insecurity.