Heidenreich

German: from the medieval personal name Heidenrich, ostensibly composed of the elements heiden ‘heathen’, ‘infidel’ (see Heiden 2) + rīc ‘power’, ‘rule’, but probably in fact a variant by folk etymology of Heidrich. The name was popular at the time of the Crusades, the sense ‘power over the heathens’ being attributed to it.