Created by Jerry Seigel, Joe Shuster, John Byrne, and Dennis E. Power
Real Name: Samuel Kent
Current Occupation: Deceased; former reporter
Parents: Joel and Mei-Lei Kent
Group Affiliation: Justice League America, Heroes of Earth
Place of Birth: Smallville, Kansas
Place of Death: Metropolis
First Appearance: Man of Steel # 1, October 1986
The original Superman, Clark Kent (actually Kal-L of Krypton) and his wife Lois had a son, named Joel, who was born without powers. In Vietnam, Joel (who had become a very bad person) was nearly killed by his own unit when he tried to burn down a village. They left him for dead, but one of the villagers, Mei-Lei, nursed him back to health.
Joel learned the errors of his ways. He took Mei-Lei as his wife, and they moved back to the Kent farm. Eventually, they had a son, Sam, who did inherit the Kryptonian powers.
Sam moved to Metropolis as an adult, and took up the role of Superman, at one point rivaling the popularity of Powerman. Tragically, though, this Superman was killed by a monster dubbed Doomsday.
As I've said before, Superman I (Kal-L/Clark Kent) was my response to the inclusion of Crossovers: A Secret Chronology of the World in the Wronskiverse. Superman II (Mon-El/Bob Kent) was my response to the Super Friends' inclusion, and Superman III (Sam Kent) was in response to the integration of the post-crisis DCU into the Super Comics Universe.
There's still one more left. Or there will be I should say. Once we move beyond.