Onjo of Baekje

Onjo, son of Goguryeo founder Jumong, established the Baekje kingdom at Wiryeseong (modern Seoul). He organized the state's early administration and military, laying the foundation for one of Korea's Three Kingdoms.

Onjo expanded Baekje's territory by subjugating local tribes in the Han River basin. He established defensive fortifications and secured the kingdom's borders against rival states.

Onjo introduced a legal code for Baekje, defining laws on property, crime, and governance. This code helped centralize authority and maintain order in the growing kingdom.