Once upon a time the dead arose and swept across the land. Children cried for lost parents and parents Mourned for lost children. The beast took heads and devoured villages in hours. One biten you were doomed. You'd come back as savages, with missing limbs and torn throats.
Many people believed the dead could be burned. So the west was laid to fire. Others believed they could be hanged. so the east was hung. People in the south believed they could be fought off and so the south was over run.