Korean History › Three Kingdoms › Baekje
King Geunchogo of Baekje
r. 346–375· Person· Rulers & states
Well documentedSolid records, physical evidence or scientific consensus.
Baekje's 4th-century conquering king, who expanded south over Mahan, struck north at Goguryeo, and reached out to China and Japan.
See it on the Korean History map →What happened
King Geunchogo (근초고왕), ruling 346–375, made Baekje the peninsula's strongest power. He absorbed remaining Mahan chiefdoms in the southwest, traditionally around 369, and in 371 attacked Pyongyang, where Goguryeo's King Gogugwon was killed. He sent envoys to China's Eastern Jin in 372 and exchanged gifts with Yamato Japan. His scholar Go Heung compiled Baekje's first official history, the Seogi, now lost.
Why it matters
He set Baekje's peak and its sea network linking China, Korea and Japan; the 371 clash began a long Baekje–Goguryeo feud.
Legacy and how we know
Samguk sagi annals, the Chinese Jin shu recording his 372 envoy, and the Nihon Shoki; the Seven-Branched Sword at Japan's Isonokami Shrine is usually linked to his reign.
Still debated
The 369 Mahan conquest rests on a reinterpreted Nihon Shoki passage, and how much territory he really controlled is debated.
Connections (3)
▸King Geunchogo of Baekje brought a golden age to BaekjeWell documented
The connection
Under Geunchogo, Baekje reached its greatest extent, from the Han River south through former Mahan lands, and briefly pressed into Goguryeo. He fixed father-to-son royal succession, opened ties with Eastern Jin and Yamato, and ordered an official history: the moves of a confident, centralizing monarchy.
When and how
Hanseong, near today's Seoul, 346–375.
How we know
The Samguk sagi's Baekje and Goguryeo annals, both recording the 371 Pyongyang campaign, and the Jin shu's record of his 372 envoy.
Debates and open questions
The exact borders he controlled, especially in the far southwest, are uncertain and partly reconstructed from Japanese sources.
▸King Geunchogo of Baekje is credited with opening Baekje's ties with Yamato JapanMostly agreed
The connection
Baekje–Yamato ties first appear clearly in Geunchogo's reign. The Seven-Branched Sword, a Baekje gift to the Wa ruler, carries an inscription commonly read as 369, and the Nihon Shoki records envoys exchanged in his time. The alliance gave Baekje a partner against Goguryeo.
When and how
Baekje and the Wa (Yamato) court, about 366–372; the sword is kept at Isonokami Shrine, Nara.
How sure are we?
The sword's inscription and Nihon Shoki entries, whose dates must be shifted by 120 years to fit; contact before his reign is likely.
Debates and open questions
The inscription's date and meaning are disputed: a gift from a senior Baekje, or tribute? Earlier informal contacts make 'opening' an approximation.
▸King Geunchogo of Baekje won a 371 victory over GoguryeoWell documented
The connection
After repelling a Goguryeo attack in 369, Geunchogo and his crown prince struck north in 371 with, records say, 30,000 troops and stormed Pyongyang fortress. Goguryeo's King Gogugwon was killed by an arrow. The blow began a long feud that Goguryeo avenged in 475 by taking Baekje's capital.
When and how
Pyongyang fortress, 371; King Geunchogo and Crown Prince Geungusu against King Gogugwon.
How we know
Both the Baekje and Goguryeo annals of the Samguk sagi record the battle and the king's death.
Debates and open questions
Which 'Pyongyang' was attacked, today's city or another fortress of that name, and the troop numbers are uncertain.