Three-Way Rivalry of Baekje, Silla, and Goguryeo

Timeline

1. 500–551Han River basin · Han River basinBaekje long controlled the lower Han River while Silla expanded northwest; the two states repeatedly fought over fortresses in the Han River basin, with Baekje at times gaining the upper hand, though Silla gradually consolidated its Gyeongwan system and pushed into the peninsula's center in the first half of the 6th century.
2. 532–562Nakdong River basin · Gyeongsang ProvinceSilla and Baekje allied and successively conquered southern small states including Gyeongwan Gaya; after Gaya's fall in 562 the southern peninsula fell into a Silla–Baekje standoff, and the three-way rivalry entered a new phase.
3. 551–600North of the Han River · Korean PeninsulaIn 551 Silla and Baekje jointly captured key positions on the north bank of the Han River, but Silla immediately seized the gains alone, breaking the alliance; thereafter Goguryeo invaded south repeatedly, Baekje and Silla also attacked each other, and the three-way war intensified, with each side seeking aid from Wa and Sui China respectively.