Promise - Jumong

Their eventual separation—where So Seo-no leaves to prevent a civil war so her sons can found the Kingdom of Baekje—is viewed by many fans as the ultimate bittersweet fulfillment of their promise to put the nation's survival above their own love. 3. The Broken Promise of the Broken Sword

In the context of Korean history and foundational mythology, the closest concept to a "promise" made by Jumong (posthumously known as King Dongmyeong) is the (다물). Jumong Promise

To reclaim the lost lands of ancient Gojoseon. In the ancient Buyeo language, the word Damul literally translates to "recovery of old territory." Jumong Promise