On January 9, 2007, the Dark Portal in Blasted Lands opened, with demons pouring out. This event signaled the beginning of the World of Warcraft: The Burning Crusade expansion, much of the content of which is accessed by going through the portal. The demon leader Lord Kazzak escaped through the portal, replacing his presence with Highlord Kruul who attacked several areas in the game world. The world event lasted for a week before the release of The Burning Crusade expansion.