It’s about time. We are now on Instagram!
Old English nylle, nelle "to be unwilling," from ne "no" (see no) + will (v.). Often paired with will; the construction in nill he, will he, once common, attested from c.1300, surviving principally in willy-nilly, which, however, reverses the usual Middle English word order. Latin expressed a similar idea in nolens volens.