Black Adam's origin story in the comics is quite complex. He was originally a slave in the fictional nation of Kahndaq. He was chosen by the wizard Shazam to be his champion. However, power corrupted him. He used his newfound powers not for good but for his own desires and to rule over Kahndaq with an iron fist.
Black Adam's origin story involves ancient Egyptian magic and a quest for power. He was originally bestowed with great powers but later turned against his benefactors.
Black Adam was originally an enslaved person in ancient Egypt who was bestowed with great powers by the gods. But his misuse of those powers led to his downfall.