I came across an interesting discovery regarding Henry VIII. Before he let himself go, Henry was a prolific athlete and often participated in jousting tournaments. However, he had two notable jousting accidents that left him with several concussions and ulcerous wounds on his legs. The concussions gave him emotional and psychological instability while his leg injuries left him in a constant state of debilitating pain. These unpredictable mood swings combined with being in pain all the time may have contributed to him becoming a tyrant. For my fantasy book, I am thinking of incorporating similar injuries to the main villain. At first, he will start out as a competent ruler, but his wounds eventually turn him into a tyrant.