Goguryeo, the northern kingdom

Goguryeo moved its capital three times: from Jolbon to Gungnae-seong on the Amnok River, in 427 to Pyongyang, and in 586 to Jangan-seong inside Pyongyang.

The Three Kingdoms period is the name Korean historians give to the centuries when Goguryeo, Baekje and Silla shared the Korean peninsula and much of the land north of it. A fourth group, Gaya, held the south coast for a long time as well. The period ends in the 660s and 670s, when Baekje and Goguryeo fell and Silla pushed the Tang army out of the peninsula. This course follows those kingdoms in eight units, starting with the largest of them, Goguryeo.

A prince who fled from Buyeo

Historians read this story with care. Large parts of it are borrowed from the founding legend of Buyeo, so it cannot be taken as a plain record. The National Institute of Korean History explains the more likely picture: groups living along the middle and upper Amnok River joined with people moving south from Buyeo, and small valley communities called na merged or were conquered over time. By the late first century these communities had settled into five units, the five bu. One of them, Gyeru-bu, supplied the king.

Three capitals

Goguryeo capitals usually came in pairs: a walled town on flat ground where the king normally lived, and a mountain fortress nearby for times of war. The first capital, Jolbon, is placed in today’s Huanren area of Liaoning, China. Wunü Mountain fortress there sits on top of a peak about 820 metres high, surrounded by cliffs on three sides.

According to the Samguk sagi, the capital moved to Gungnae-seong, in today’s Ji’an on the Amnok River, in the year 3 CE. Some historians date the move later, to around 209, because a Chinese history describes a new capital being founded then. Gungnae-seong was a square stone city where two rivers formed a natural moat, paired with Hwando fortress in the hills behind it. The pair did not always hold: in 342 an army of the Former Yan state took the capital.

In 427 King Jangsu moved the capital again, to Pyongyang. The plain there was wide, farming was rich, and the area had been a centre since the days of Gojoseon. Older textbooks explained the move simply as a push to the south; recent studies add economic reasons and the wish to weaken powerful noble families. In 586 the court moved once more inside Pyongyang, to Jangan-seong, a walled city whose outer walls ran about 16 kilometres.

From crisis to the strongest state

The fourth century was hard for Goguryeo. After the capital fell in 342, King Gogugwon was killed in 371 while defending Pyongyang against a Baekje attack. His son, King Sosurim, answered with reforms. Buddhism was officially accepted in 372, and a law code was issued in 373, which put the king’s written law above the decisions of noble councils. These changes prepared the ground for the great expansion under King Gwanggaeto and King Jangsu in the late fourth and fifth centuries, covered in unit 6.