When Jumong crossed the river to escape the wrath of the princes, he left many things behind in Buyeo. His mother, the egg-laying Yuhwa, became a respected figure in her own right, judging by the fact that she was given the same burial ceremonies as an official queen of the court. So things went well for her. But Jumong also had a wife, and his child grew up without a father back in Buyeo.
Yuri, the son, had the same prowess in archery as his father. He would go out and practice his skills with the bow and arrow, much to the chagrin of everyone who was in proximity of his shots. One day he aimed his arrow at a jar an old woman was carrying. The woman was furious, fed up of his shenanigans, and told him off, saying that he was so ill-mannered because he grew up without a father. This hurt the young boy, who went back home and asked his mother about his father. Yuri’s mother told him everything about his father, Jumong. It turned out that before escaping, Jumong told his wife that he buried half his sword and had hidden it, and that when his son comes of age, he was to find the sword. Then both mother and son should cross the river and bring the sword half so that they can live together.
Yuri was determined to complete the task his father had given him. He searched through the kingdom until he finally managed to find the sword hidden under a tree. Yuri and his mother then reunited with Jumong at his new kingdom. King Jumong welcomed his wife and son with open arms, and, re-uniting the two halves of the sword, declared Yuri to be his successor.
In most myths and fairy tales the story ends here: the son is reunited with the father, and everyone lives happily ever after. But this story asks another question: what about those who are not the prodigal son, the people who were close to the father, but not part of the fable? For King Jumong had re-married, in order to tie himself with the other leading tribes, to a woman named Soseono, and they had two sons: Onjo and Biryu. When Jumong embraced Yuri and welcomed him as his heir, Onjo Biryu and Soseono looked on nervously.
And they were right to be nervous. It didn’t take long for people to claim that Biryu, the oldest of Soseono’s sons, should be the rightful successor of Jumong. Yuri did not take that lightly. The records talk about Yuri going on hunting trips. This was normal enough for a prince or king, but Yuri’s hunting trips always had the unfortunate habit of ending with certain ministers of court “disappearing.” This was probably the first, but certainly not the last, purge in a Korean palace. The purges were so brutal that some modern day historians believe Yuri was in fact not Jumong’s son, but a usurper from Buyeo.
Yuri did eventually become second king of Goguryeo, and Jumong’s other sons knew that this was not the place for them. Along with their mother, Biryu and Onjo crossed the waters and moved southward. They reached Bukhan mountain, the mountain you can see behind the palace in downtown Seoul today. The brothers argued about where they should set up their country, and eventually split ways. Biryu moved his founded a city close to present day Incheon, while Onjo, the younger brother, took a few ministers and built a town on the other side of the Han River. Onjo named the place Sipje, “the ten vassals.”
The land around Incheon is very close to the ocean, and it is full of salt water and marshes. Not the best place to build a city. There was not a lot of land that was fertile enough for crops, and the marshes were full of diseases. It did not take long for Biryu to realize that his city was not sustainable. The city didn’t last very long, and, ashamed, Biryu moved to his younger brother’s town. He committed suicide shortly after, and Onjo welcomed his brother’s subjects. Now Onjo became the founder of the new kingdom, and with all his subjects reunited, he renamed his land Baekje, “the hundred vassals.” The traditional date of founding is 18 BCE.
One of the biggest challenges facing this new soon-to-be-kingdom was its neighbors. The southern regions of Korea was occupied by primarily the Samhan, the group of confederacies that grew out of the former Jin state. There were also the Chinese Han commanderies, especially Nangnang, which were there to frustrate the plans of any state getting a little bit too big. The biggest problem King Onjo and his little state encountered, though, were the Malgal.
The Malgal were a semi-nomadic people that crossed the Han river, raiding and pillaging villages. They set their sights on Baekje, which had grown quite prosperous, and attacked the area a few times. Onjo led his troops- this was when kings were expected to be head of the army as well as political rulers- to defend his place. And finally in 5 BCE moved his people down south to find a more secure area.
Going down south put King Onjo in dangerously close proximity to the center of the Mahan confederacies. He sent a message alerting the Mahan king about the move, and they were allowed into the area. But Onjo already had his sights on a bigger prize than just defending his small state: he wanted to absorb the Mahan confederacies under his rule. Using the threats of the Malgal to his advantage, King Onjo managed to train troops right under the unsuspecting Mahan king. And then, using a hunting trip as an excuse, King Onjo led his troops and took over many Mahan fortresses.
The Mahan king committed suicide, but not before sending a message imploring that the king of Baekje treat the Mahan people with mercy. Respecting the Mahan king’s dying wish, Onjo received the Mahan subjects and allowed them to live under his protection. This was a mighty blow to the Mahan confederacies, but not the end. Baekje would continue for many years after to absorb Mahan territory, as well as defend themselves from the relentless Malgal troops.
Onjo, the unlikeliest of Jumong’s three sons, became the founder of the new area of Baekje. He died in 28 CE, and set the stage for his land to became one of the powerful three kingdoms, a kingdom that would play an pivotal role in the formation of not only Korea, but Japan as well. Baekje’s expansionist tendencies would soon prove to be dangerous, though, as they were to clash very shortly after Onjo’s death with another expanding kingdom from the south, the Silla.