Why is the ninth month called September?
division of certain English counties (equivalent to a hundred in other places), Old English wæpengetæc, from Old Norse vapnatak, from vapna, genitive plural of vapn "weapon" (see weapon) + tak "touching," from taka "to take, grasp." Perhaps it originally was an armed muster with inspection of weapons, or else an assembly where consent was expressed by brandishing swords and spears.
an administrative division of the English counties of York, Lincoln, Leicester, Nottingham, Derby, and Rutland, first clearly referred to in 962/963 and corresponding to the "hundred" in other parts of England. The term wapentake is of Scandinavian origin and meant the taking of weapons; it later signified the clash of arms by which the people assembled in a local court expressed assent. Danish influence was strong in those English counties where wapentakes existed.