The continent of Assail was situated between Genabackis and the Letherii continent and was held to be the most dangerous and hostile part of the Malazan world. The Crimson Guard mercenaries and some T'lan Imass were known to have engagements there. The Malazans knew of the existence of Assail and the Wrecker's Coast along its shores, but the Empire had chosen to make no incursions there due to the extreme danger of the land. It was known that the continent was dominated by a human leader (or possibly several human leaders) (Memories of Ice, pg. 573) whose armies are powerful enough to destroy T'lan Imass forces, the Ifayle and the Kerluhm. Little else was known of it.
There are some hints in Return of the Crimson Guard that indicate that the inhabitants, or at least some of them, may be at least part Jaghut. While the Guardsmen are escaping from Assail it is mentioned that the only word the guardsmen use that the native defenders recognize is Jaghut, and that the primogenetrix's royal line makes her very resiliant, including protecting her from the guards sorceorous attacks, and gives her fast healing. She states that that word (Jaghut) is forbidden in her land and that "Ancient truths remain alive somewhere. One place too many for her and her kind". This seems to indicate that at least one faction on Assail is lead by a family of Jhag, if not full Jaghut. Later in the novel, Kyle later mentions that the Jhag are feared in his peoples legends. His people also stay away from "Assail lands" and even Kyle says that he could sense the alien strangness of those lands from a great distance.