During the medieval period, imposing castles were scattered all over Europe and the Middle East, overlooking the towns or villages they controlled, and housing a powerful king or noble. To any invading force or envious rival, a strong castle was essential in projecting the force its occupant held. Before the medieval period, the Western Roman Empire had long enjoyed power across the continent thanks to the strength of its highly trained, professional military. But when the empire fell in 476 AD, and local kings and lords filled the space they left behind, despite the constant warfare that followed a standing army was not deemed essential. Medieval warfare was focused around the siege of a castle, with the plan of invaders to either try and take it for themselves or pummel it into terms of surrender. From around the eleventh century, castles became more prominent and far harder to breach by normal means, and in return, that led to more effective and destructive siege technologies.