Army. When peace came, the Emperor went boating on this lake. A huge turtle appeared before him, spoke in a human voice, asking the Emperor to return the sword. “The world will only be at peace if all people let go of their weapons,” the turtle said. Astonished, the Emperor held out his beloved sword. The turtle took it with his mouth, disappearing under water. From then on, the lake was named Hoàn Kiếm—the Lake of the Returned Sword.