Attuma was born into the tribe of Homo Mermanus who eschewed civilization to live as underwater nomadic barbarians. By some unrecorded method, Attuma was endowed with strength far surpassing that of his people. Nearing adulthood, Attuma learned of a prophecy, in the lost Atlantean Chronicles, of a conqueror who would take the empire of Atlantis by force. Believing himself to be that conqueror, Attuma moved to a position of leadership over his barbaric brethren, and launched an attack on the city of Atlantis and its ruler, Prince Namor, also known as the Sub-Mariner. He is Namor's archenemy.