Pyeongwon of Goguryeo

King Pyeongwon of Goguryeo (ruled 559—590) was a 6th-century Korean monarch, the 25th ruler of Goguryeo, the northernmost of the Three Kingdoms of Korea. King Pyeongwon was also known as King Pyeonggangsangho. His birth name was Yangseong (though the Suishu and Tangshu have him as Tangseong).

The years of Pyeongwon's rule are generally agreed upon by historians, but his year of birth has not been established with any degree of certainty. It is known that he was the eldest son of King Yangwon and became crown prince in 557, two years before assuming full power. He is said to have been courageous, and skilled in horseriding and archery.

By this time, royal power had been significantly eroded by the aristocracy. Concerned for the people, he encouraged agricultural and sericultural developments and reduced the royal cuisine.

He maintained tense but relatively peaceful relations with the Göktürks and the various Chinese dynasties, briefly battling the Northern Zhou at the Liaodong Peninsula in 577. He frequently sent tributes to the Chen Dynasty, Northern Qi, Northern Zhou and Sui Dynasty. As the Sui Dynasty united China, King Pyeongwon prepared for the impending war.

The southern border with the other two Korean kingdoms was relatively peaceful as the Silla-Baekje alliance fell apart. In 586, he moved the capital to Jangan fortress.

In 590, the king received news that the state of Chen had fallen and was greatly alarmed. For defense purposes he ordered troops into training and the augmentation of military provisions.

The rule of Pyeongwon came to an end in 590, which is the year of his death according to Samguk Sagi, but there is no specific documentation to confirm the circumstances.

He was given the posthumous royal title of King Pyeongwon.