The Ottonian Duke Henry the Fowler (919–36), elected German king in place of Conrad of Franconia, succeeded where his predecessor had failed. His personality alone checked the autonomy of the secular magnates and he promoted ecclesiastical ones to the principal officers of state. He laid the foundations for Saxon ascendancy in the west with the reacquisition of Lotharingia. He gained the initiative in the east by turning back the Hungarians.To protect the realm from barbarian incursion — and internal opposition — Henry revived Roman fortification where possible and constructed innumerable forts and a series of fortress towns,which usually consisted of a citadel on high ground overlooking the surrounding terrain and protecting a ward for the rehoused local population — after the pattern long-adopted on the much smaller scale of the individual landholder.