Erok's story is documented when Clark Kent is asked to get information on Superman's family tree. Kal-El (Clark) also wants to find out about his family so he travels through a few galaxies with his cousin Kara Zor-El (Supergirl). They find that Kal-El looks just like Erok and that Erok took on the name El (meaning star) as a surname and that the name of his first born son was Kal (child), Kal-El.
Erok becomes "Erok of the Star," the founder of the House of El (KC No. 3, Nov 1981: "The Race to Overtake the Past").