up, rouse to activity" is from c.1600. Originally strong declension (p.t. awoc, pp. awacen), already in O.E. it was confused with awake
(v.) and a weak p.t. awæcnede (modern awakened) emerged and has since become the accepted p.t. form, with awoke and awoken transferred to awake. Subtle shades of distinction determine the use of awake or awaken in modern English. Related: Awakening.