"handle of a tiller," late 13c., from Old English helma "rudder; position of guidance, control," from Proto-Germanic *halbma- (cf. Old Norse hjalm, Old High German helmo, German Helm "handle"), from PIE *kelp- "to hold, grasp" (see helve).
"a helmet," c.1200, from Old English helm "protection, covering; crown, helmet," and perhaps also from cognate Old Norse hjalmr, from Proto-Germanic *helmaz "protective covering," from PIE *kel- "to cover, to hide" (see cell). Italian elmo, Spanish yelmo are from Germanic.