[7] Moreover, William III also concluded an inheritance treaty on Katzenelnbogen with the Electors of Saxony and Brandenburg, under which he would compensate his sisters Elisabeth and Matilda of Hesse (married to John II, Duke of Cleves) with 50,000 florins.

[7] When Elisabeth's brother William III "the Younger" of Upper Hesse died childless on 17 February 1500, the scenario outlined in the engagement treaty of 1471 emerged.

[2] Indeed, Elisabeth laid claim to all her brother's bequeathed lands, and John also immediately jure uxoris assumed the title count of Katzenelnbogen.

It led to a half-century long, difficult and costly legal battle between Hesse and Nassau known in German as the Katzenelnbogische Erbfolgestreit ("Katzenelnbogen Succession Struggle").

[6] In the opening phase, William II "the Middle" of Hesse (died in 1509) employed much military violence in order to enforce his claim on the County of Katzenelnbogen.

[5] Although Nassau had good ties with Emperor Charles V and thus managed to secure a favourable political judgment in 1524 (the Tübinger Urteil), William could do little with this in practice, because he had no means of enforcing his rights militarily.

[2] In compensation, William received 600,000 florins for his claims to the inheritance, a quarter of which was to be paid by Hesse in land and the rest in money over a period of eight years.

[1] Nassau was given the Hessian quarter of the county of Diez, including the districts of Camberg, Weilnau, Wehrheim, Ellar, Driedorf, and half of Hadamar.