An Arabic poet and mystic. More properly, his name was Abd al-Azrad. It is said that, as a young man, he spent ten years alone in the desert, studied under wizards, and visited Irem, the Nameless City, and a dangerous-sounding shrine called the Black Mosque.

He traveled throughout much of the Middle East, sometimes following masters both human and otherwise, and sometimes leading followers of his own. He isn't known to have ever taken a wife and is said to have lived as a holy man, though he didn't live a particularly holy life. In fact, it was said that he was responsible for the deaths of at least a hundred people who he sacrificed to various evil gods, and it was said that he raised so many demons and consorted with so many horrors that even the most powerful of the djinn feared him.

Later in his life, he wrote a book on magic called "Kitab al-Azif", which was retitled "Necronomicon" when it was eventually translated into Greek. It is solely for his work with the Necronomicon that his reputation as the world's greatest chronicler of the supernatural -- and as a madman -- is based.

According to his 12th century biographer, Ibn Khallikan, he worshipped Cthulhu and Yog-Sothoth and died in 738 AD when he was mysteriously torn apart in broad daylight before a marketplace crowd in Damascus.

"History of the Necronomicon" by H.P. Lovecraft
"The Nameless City" by Lovecraft
"The Doom of Yakthoob" by Lin Carter
Encyclopedia Cthuliana by Daniel Harms, p. 1