Beginning: Scholars generally believe that the earliest kingdoms or states on the Korean Peninsula first began to form during the Bronze Age (1000 - 300 B.C.). Of these, the kingdom supposedly founded by Dangun, generally known as Gojoseon or Old Joseon, soon emerged as the strongest and had consolidated it’s power by the beginning of the fourth century B.C.
As Old Joseon’s strength grew, China became more and more concerned. Therefore, the Chinese Emperor Han Wuti launched an invasion in 109 B.C. and destroyed the kingdom the following year. Four commanderies were established to administer the northern half of the peninsula.
Within a century, though, a new kingdom called Koguryo (or Goguryeo) (37 B.C.- 668 A.D.) emerged in the northern half of the peninsula. Koguryo was a nation of warriors led by aggressive and valiant kings such as King Gwanggaeto (r.391 - 410). It conquered neighbouring tribes one after another and expanded in virtually every direction. It was Koguryo which finally drove the Chinese out of their last commandery, Nangnang (Lo-lang in Chinese), in 313 A.D. At it’s height, it’s territory thrust deep into Manchuria and stretched well into the southern half of the Korean Peninsula.
Tombstone of Koguryo King Gwanggaeto (r.391 - 410), built in 414 in Tong-gou, Jian city, Jilin province in China.