According to Square's official website
Then, thirty years ago, Ehb's king was murdered, and blame was cast upon the Legion. Led by the young and charismatic Jeyne Kassynder, the people rose up and slaughtered the 10th Legion, tearing down their proud chapterhouses and estates.
With the fall of the Legion, the kingdom has fractured into petty states and free towns. Most of the country has fallen under the sway of Jeyne Kassynder, who controls the Church and eastern Ehb. Her power is steadily growing. The royal court has retreated to the mountain fastness of Glitterdelve, in the west, and the bustling city of Stonebridge has declared itself a free and independent republic.
Only a scattering of Legion descendants survive. Many were hunted down and slain by Jeyne Kassynder, while others fell victim to the mobs of common folk who rose up to sack their estates. But a network of descendants endures, organized by an elusive old man - the Venerable Odo - believed to be the last surviving legionnaire. He has protected the children of Legion blood and kept them safe from Jeyne Kassynder.
Now a gathering has been called in the remote Rukkenvahl, in the north. Odo has asked all the Legion descendants to assemble, in an attempt to rebuild the Legion and take back their kingdom from Jeyne Kassynder, before it is too late...
So to answer your question Jeyne is hunting down anyone remotely related to the Legion because of the supposed involvement in the regicide 30 years ago. She controls the Church and must of the eastern land of Ehb