But, who were these three founding members, and what did they want with Superboy as a member?
Rokk possesses the power of magnetism, native to Braalians, but his ability was stronger due to being born on Earth, with its stronger magnetic fields.
Rokk was on a spaceship headed for Earth, when he met two other teenagers who would change his life forever.
Imra came aboard the ship headed to Earth, where she got an early chance to use her powers to thwart the assassination of industrialist R. J. Brande, as well as drawing the attention of the third charter Legion member.
This act also unhinged the untwinned Mekt (Winath residents were usually born as twins), who left home, with his brother, Garth, heading to Earth to enlist the help of the Science Police to find the missing boy.
Garth got distracted, meeting Rokk along the way, and noticed a beautiful young girl board the flight (Imra) at Titan (while Rokk hoped he could get a job with R. J. Brande).
While disembarking on Earth, two assassins planned to kill R. J. Brande, except they hadn't counted on a telepath picking up their plans, and two boys using their respective powers to stop the assassins.
All this (and a little bit more), and it is time to catch up to the story presented in the Legion's first appearance, where they enroll the young Kryptonian from Smallville.
But, it was his adventures as a boy, that started in More Fun Comics #101 (January-February, 1945) by Jerry Siegel and Joe Shuster, (with a rare time that Green Arrow took the cover over Superboy) that continued on through a few issues of More Fun Comics, before transferring over to Adventure Comics, where Superboy was the main feature, learning how to get along, hiding his identity from the prying eyes of Lana Lang...and, where the charter members of the Legion of Super-Heroes came back to recruit Superboy as their 13th member in Adventure Comics #247.
Mon-El, end up as a member as well? When time permits, more facts of the Legion will be revealed....