Apocalypse is an ancient mutant, one of the oldest on Earth, who has been around for over 3000 years. Who was shaped by the cruelty and brutality that he experienced in his youth in Pharaonic Egypt, and become a believer in genetic darwinism. Survival of the fittest is his creed, and all he does has been to advance that vision. Continuously testing the sentient lifeforms of Earth, especially his fellow mutants, to see if they were worthy of evolution and ascendancy. He at times has orchestrated wars from the shadows and at other times he led armies himself.
Cultures have worshiped him as a god of war or death, and various organizations have knowingly or unknowingly done his bidding. Clan Akkaba is one such organization, having been around for 1000s of years, a worldwide network of mutants, which by the 21st century had a hidden city below the ice of the North Pole. Apocalypse has access to technology that is superior to not only that of Earth but to that of many alien civilizations, being the technology of the Celesials (space gods) and has used their technology to increase his power (e.g. cybernetics).
Apocalypse has clashed many times with the X-Men and their allies, and his agents have fought other heroes like the Avengers and the Hulk. Once he slaughtered a tribe of the demonic N'Garai and twice he defeated Dracula. Once in the 15th century, when Dracula's army was slaughtered by his Dark Rider and again at the end of the 19th century, when he defeated Dracula and his legions of vampires and human thralls. Recently Apocalypse like most of mutantkind has moved to the island of Krakoa where he now sits on its Quiet Council.