King Onjo

King Onjo is remembered as the founder and first ruler of Baekje, which he established in 18 BC. According to the Samguk Sagi and Samguk Yusa, he was a son of Dongmyeongseong (Jumong), the founder of Goguryeo, and Soseono; when his half-brother Yuri was named crown prince of Goguryeo, Onjo felt threatened and journeyed south with his mother, settling in Wiryeseong and founding his own kingdom. The Baekje he created went on to stand alongside Goguryeo and Silla as one of the pillars of Korea's Three Kingdoms period.