The Azure Book of Biluous is the Authority on the Art of Auram, a massive work in thirty volumes and the magnum opus of Biluous of Bonisagus, composed over many years in the tenth century, and added to the Great Library at Durenmar in 996. Biluous was a storm Magus of great skill, and perforce was the progenitor of his own unique lineage which spans four Hermetic Houses. The Azure Book has never been surpassed, although many inferior copies exist. It was largely on the strength of this work that Biluous' skill at such came to be known throughout the Order, and that he was eventually granted the title of Archmagus.