Gwanggaeto the Great
Northern conquests

In 395, while his campaign against Baekje was ongoing to the south, Gwanggaeto made an excursion to invade the Khitan Baili clan to the west on the Liao River, destroying 3 tribes and 600 to 700 camps. In 398, Gwanggaeto conquered the Sushen people to the northeast, who were Tungusic ancestors of the Jurchens and Manchus.

In 400, while Gwanggaeto was occupied with Baekje, Gaya, and Wa troops in Silla, the Xianbei state of Later Yan, founded by the Murong clan in present-day Liaoning, attacked Goguryeo. Gwanggaeto repulsed the Xianbei troops. In 402, Gwanggaeto retaliated and conquered the prominent fortress called 宿軍城 near the capital of Later Yan. In 405 and again in 406, Later Yan troops attacked Goguryeo fortresses in Liaodong (遼東城 in 405, and 木底城 in 406), but were defeated both times. Gwanggaeto conquered all of Liaodong. By conquering Liaodong, Gwanggaeto recovered the ancient domain of Gojoseon; Goguryeo controlled Liaodong until the mid-late 7th century.

In 407, Gwanggaeto dispatched 50,000 troops consisting of infantry and cavalry and won a great victory, completely annihilating the enemy troops and pillaging about 10,000 armors and countless war supplies; the opponent can be interpreted as Later Yan, Baekje, or Wa.

In 410, Gwanggaeto attacked Eastern Buyeo to the northeast.
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