The "King of Rohan" is the ruler of the fictional realm of Rohan, a kingdom in Middle-earth created by author J.R.R. Tolkien. Known for its vast grasslands and strong cavalry, Rohan is home to the Rohirrim, skilled horsemen who play a crucial role in the battles against the forces of Sauron. The most notable King of Rohan in Tolkien's works is Theoden, who leads his people during the events of "The Lord of the Rings." Under his leadership, Rohan allies with Gondor to fight against the invading armies of Saruman and Sauron, showcasing themes of bravery and unity.