King Gwanggaeto, also known as Gwanggaeto the Great, was the 19th king of the Korean kingdom of Goguryeo. He reigned from 391 to 413 AD and is celebrated for his military conquests and territorial expansion. Under his leadership, Goguryeo grew to include parts of modern-day China and Mongolia, making it one of the most powerful states in East Asia during his time. Gwanggaeto is also known for his efforts to promote Buddhism and strengthen the central government. His legacy is commemorated in the Gwanggaeto Stele, which details his achievements and serves as an important historical source for understanding the period.