Morian Zenas was a member of the Mages Guild. He wrote the book On Oblivion, and is considered a well-respected source of information about the many planes of Oblivion. He was a master of Conjuration, as was his apprentice, Seif-ij Hidja Morian is also a master of many different subjects of magic.
He made it his life's ambition to find a way in to the realm of Oblivion. During experimentation with portals, his mind became interconnected with that of his apprentice. He then met with the Dunmer wizard Divayth Fyr, who taught him a method through exploiting a series of portals to various realms created by a Telvanni wizard long missing and now presumed dead. He used this method to then cross over to the realm of Oblivion and Seif-ij was able to document it, with their telepathic connection.
Morian Zenas traveled through Ashpit, Coldharbour, Moonshadow, Quagmire, and Apocrypha. After finally reaching Apocrypha his lust of knowledge takes over, until his thoughts become nothing more than unintelligble whispers. Zenas eventually was lured into the world of research and study, and is believed to have gone back to Apocrypha, or may have lost his sanity and fell into the stacks of Madness in the Shivering Isles.