sentences:  Their success was built upon the relative political stability that the Kassite monarchs achieved.They ruled Babylonia practically without interruption for almost four hundred years—the longest rule by any dynasty in Babylonian history.Formation of Kassite power
  
  The transformation of southern Mesopotamia into a territorial state, rather than a network of allied or combative city states, made Babylonia an international power, although it was often overshadowed by its northern neighbour, Assyria and by Elam to the east.