The purpose of this study is to make a lexical comparison of two medieval poems, both songs of William--one French, one German--in which there existed a wealth of narrative and thematic parallels. La Chanson de Willame was written by an unknown author around 1150, and Willehalm was composed around 1200 and, as claimed by the author, was the result of an oral transmission by French witnesses to the noble conquests of the partially legendary hero William. Because of the dominant theme of war in both poems, the lexical comparison is restricted to words pertaining to weapons. The names of offensive weapons, engines of war, and defensive weapons total sixty-four Middle High German words and forty-five Old French words which described either the different weapons or the various parts of weapons. Of the Middle High German words forty-two are of Germanic origin, four of these first appear during the Middle Ages, namely MHG lanze, armbruste, harnasch, and buckle. Twenty words were borrowed from Latin, one from Old Indic, and one is of unknown origin. Of the Old French words twenty-nine derive from Latin, six from Frankish, seven from Germanic, two from Gaulic, and one from Old Saxon. It is observed that there was an inverse ratio of Latin and Germanic derived words between the two poems. Also, the Middle High German poem featured more variety in military vocabulary, whereas the Old French version featured more variant names for the same weapon. Of this variant nomenclature only three word pairs point to borrowing on the part of Middle High German from Old French, around the year 1200, namely MHG lanze, mangen, and kolze. In most other cases the already existing German term or loan translation prevailed.