Assur was a baron of The Burning Hells. The favored of the Lord of Terror, Diablo. He had bright and glowing red eyes, and horns protruded from his shoulders, elbows and knees. He wore a primitive loincloth, a belt and a giant sword. On his chest was an emblazoned glyph, a blessing from Diablo that can only be cast once a millennium, that made Assur invulnerable to the hand of any living thing.
Assur was slain by Siggard at the city of Brennor after Assur's army had initially undertaken a successful siege. Demonsbane puts the year of this battle as 302, and it is considered one of the first great battles of The Sin War.
Assur is the main antagonist in the novel Demonsbane.
| Prime Evil — Tathamet|
Prime Evils — Diablo • Mephisto • Baal