King Jangsu of Goguryeo (394–491) (r. 413–491) was the 20th monarch of Goguryeo, the northernmost of the Three States of Korea. He was born in 394, the eldest son of Gwanggaeto of Goguryeo. He became crown prince in 408, and upon his father's death in 413, became King at the age of 19.
He reigned over the peak of Goguryeo's power, building on his father's territorial expansion. He is also noted for the Gwanggaeto Stele. His posthumous name means "long life."
Read more about Jangsu Of Goguryeo: Early Reign, Northwestern Campaign, Southern Expansion, Relations With China and Rourans, Death and Legacy