Jayne Kassynder was born approximately fifty years prior to the beginning of Dungeon Siege III. She is the illegitimate daughter of the former king of Ehb and the last leader of the Archons. Thirty years before Dungeon Siege III, when Hugh Montbarron of the 10th Legion sought to unseat the mad king and inadvertently killed him, she inspired the citizens of Ehb to rise up against the 10th Legion. When Hugh and his men fled into the forest that would become known as the Mournweald while the Legion died, she gave chase, and blackened the forest when she struck down Hugh and his comrades.
For the next thirty years, she would wage civil war on the royal family, believing the Legion to be destroyed and wanting to secure her place on the throne. However when a survivor by the name of Odo sent out messages to gather the remaining legionaries together, she sent out an army of Lescanzi mercenaries to wipe them out. She almost succeeded, however a handful escaped the ambush, including Odo, Martin Guiscard, Lucas and Katarina Montbarron, Reinhart Manx, and Anjali. These men and women would serve as the foundation for a resurgent 10th Legion which would be Kassynder's downfall.
She met the resurgent Legion face-to-face during the Siege of Glitterdelve Mine, where she hoped to crush the remaining royalists. Instead her forces were slaughtered by the 10th Legion, who used an alliance they struck with the Free Republic of Stonebridge to launch a counterattack using the city's automaton army. They attacked the Spire, command nexus of the Azunite forces, and defeated her. She then fled to the Mournweald hoping to resurrect the old creator gods and their armies, and nearly succeeded, but was ultimately stopped by the combined power of the 10th Legion and the Radiant Youth. Her fate, at that point, was left up to the new Legion.