Old English hergian "make war, lay waste, ravage, plunder," the word used in the "Anglo-Saxon Chronicle" for what the Vikings did to England, from Proto-Germanic *harjon (cognates: Old Frisian urheria "lay waste, ravage, plunder," Old Norse herja "to make a raid, to plunder," Old Saxon and Old High German herion, German verheeren "to destroy, lay waste, devastate"), from *harjaz "an armed force" (cognates: Old English here, Old Norse herr "crowd, great number; army, troop," Old Saxon and Old Frisian heri, Dutch heir, Old High German har, German Heer "host, army," Gothic harjis), from PIE root *koro- "war" also "war-band, hose, army" (cognates: Lithuanian karas "war, quarrel," karias "host, army;" Old Church Slavonic kara "strife;" Middle Irish cuire "troop;" Old Persian kara "host, people, army;" Greek koiranos "ruler, leader, commander"). Weakened sense of "worry, goad, harass" is from c.1400. Related: Harried; harrying.