late 13c., from O.E. þanone, þanon "from that place" + adverbial genitive -es. O.E. þanone, þanon is from W.Gmc. *thanana (cf. O.S. thanana, O.N. þana, O.Fris. thana, O.H.G. danana, Ger. von dannen), related obscurely to the root of then, and
ult. from PIE demonstrative base *to- (see the). Written with -c- to indicate a voiceless "s" sound. From thence is redundant. Thenceforth is late 14c.; thenceforward attested from mid-15c.