Frank Schechter introduced the concept of trademark dilution to American readers in his 1927 Harvard Law Review article “The Rational Basis of Trademark Protection.”2 He concluded the article by noting that his formulation of the concept “is fortified by the doctrine that has developed within recent years in German law on this same point.”3 In waiting until the end of his article to refer to the German case law, Schechter effectively implied that dilution was a home-grown American idea – indeed, that it was Schechter’s own, original idea – and that the German courts just happened to have come up with a similar notion. In fact, Schechter appears to have taken the concept of trademark dilution and much of the rhetoric he used in describing it – including “selling power” and the very term “dilution” – from a single German trial court opinion, specifically, the opinion of the Elberfeld Landgericht in the 1924 Odol case.4 The enormous significance of the Odol opinion for American and global trademark law still remains unappreciated. In honor of Annette Kur’s path-breaking and decades-long work in forging mutual understanding between the European and American trademark law systems, presented here is the first full translation into English of the Odol opinion, trademark dilution’s “ur-case.”5