An Etymological Dictionary of the German Language/Annotated/Kraft
Kraft, feminine, ‘strength,’ from Middle High German kraft, Old High German chraft, feminine, ‘strength, power, force of an army, multitude, abundance’; compare Old Saxon craft, masculine and feminine, Dutch kracht; Anglo-Saxon crœft, masculine, with the High German meanings, also ‘mental capacity, art, science,’ hence English craft (the corresponding crafty shows prominently the last specialisation of meaning within the mental sphere); Old Icelandic kraptr, masculine, ‘strength,’ Modern Icelandic krœfr, ‘strong,’ exhibits the stem without the dental suffix; yet Old Icelandic krefja, ‘to beg, demand, challenge,’ as well as Anglo-Saxon crafian, English to crave, seems, on account of its meaning, not to be connected with the substantive. No certain cognates are found in the non-Teutonic languages.