Ⅱ. The Three Kingdoms Develop into Centralistic Nations

Numerous small states that arose with the spread of the iron culture became incorporated into the three kingdoms of Goguryeo, Baekje and Silla during the 4th and the 5th centuries. Goguryeo, which expanded power through confrontation with the Chinese forces in the northern part of the Korean peninsula, emerged as a major empire of Northeast Asia in the 5th century. By the 7th century, Goguryeo engaged in numerous confrontations with unified China and triumphed. Meanwhile, Baekje, which arose along the Han River, greatly expanded its territory from the latter part of the 4th century and engaged in active maritime activities. Silla, which emerged in the southeastern part of the Korean peninsula, cultivated national strength following the 6th century and became a central force of the Three Kingdoms by confronting Baekje and Goguryeo.