Long ago, Three Sovereigns descended from the heavens onto the land of Militia. According to legend, the Three Sovereigns used their powers to bring order to the land. One became the sun and bathed the world with its sunlight. One became the moon and healed the world with its moonlight. One became the sea and nurtured the world with its waters. It is foretold that a time of strife shall arrive.

"When Militia is shrouded in darkness, the souls of the Three Sovereigns shall be entrusted to the Gundams. Only with guidance from the Gyokuji, shall they exorcise the land from darkness..." - Militia Legend, "G Records"-

That time of strife will be known as Sangokuden, and that time has come upon us.