Sul-El was born a citizen of Kandor on the planet Krypton several hundred years ago. Sul-El's interest in astronomy was born of an even greater passion for history and the sciences in general. Researching the work of one of his distant ancestors, Kil-Gor, he discovered a means by which to convert lenses made of volcanic glass into a working telescope. He spent endless nights out on the balcony of his laboratory staring up at the moons of Krypton.
One evening, he noticed something that he initially believed was a comet. Upon closer examination, Sul-El discovered that it was actually a space-vessel. At this point in time, Krypton had yet to make First Contact with any form of extraterrestrial life, so such a discovery excited Sul-El greatly. He rushed to the governor's office in Kandor to speak with the Drygur, Usk-Mar. He told him of his discovery, but Usk-Mar dismissed his claims as wild fancy and heresy. Sul-El warned that the vessel he sighted was on a direct course for Krypton, and it was possible that it might be an advance scout ship for an alien invasion. Still, the Kryptonian statesman paid him no mind.
As it turned out, Sul-El's greatest fears proved true. A warlike alien race known as the Vrangs invaded Krypton and took control of the continent of Lurvan. They enslaved the Kryptonian populace and put them to work in the mines of the Crystal Mountains. Even Sul-El's young son, Hatu-El, worked alongside his father, bound in chains, mining minerals for their Vrang masters. Little did Sul-El realize that Hatu-El would one day lead a slave revolt that would liberate Krypton from Vrang control.
It is not known the manner in which Sul-El eventually died, and it is just as likely that he may have passed away prior to the liberation of Krypton. A statue of Sul-El holding a telescope was erected in the House of El memorial hall at New Kandor on the planet, Rokyn.
Sul-El did not possess any superhuman powers while living under a red sun. Had he lived on a world revolving around a yellow sun, he would have developed physical attributes similar to that of Superman.
Sul-El was an accomplished scientist with a keen knowledge of astronomy.
- This version of Sul-El (Earth-One), including all history and corresponding appearances, was erased from existence following the collapse of the original Multiverse in the 1985–86 Crisis on Infinite Earths limited series. Even though versions of the character may have since appeared, this information does not apply to those versions.
- Sul-El's final fate has never been revealed, but it is reasonable to assume that he passed away long before the ultimate destruction of Krypton. It is possible that he may have even died at some point during the Vrang occupation.
- Sul-El is an analog to the 17th century Italian physicist Galileo.
- 1 Appearances of Sul-El (Earth-One)
- 1 Images featuring Sul-El (Earth-One)
- Quotations by or about Sul-El (Earth-One)
- Character Gallery: Sul-El (Earth-One)