[3] Apart from that, John had already distinguished himself valiantly in wars with Hesse and the Electorate of Mainz, when he loyally stood by his elder brother Adolf and, as long as the latter was alive, fought many important battles with him.

[6] Likewise, they promised each other, out of conviction of mutual advantages, not to inflict any violent advances on each other, and to allow the preferences of one and the other to apply, which had been established by older decrees.

Adolf hereby tacitly renounced his right to the part of Nassau-Hadamar and the districts of Herborn, Haiger and Löhnberg, which he could have claimed in advance from the marriage contract with the heiress of the County of Diez.

[4][11] John had used this extremely clever man, perhaps as notorious as his name sounds (his surname translated into English was Gallowswood), for reconnaissance and negotiation for a long time.

[7][note 6] When the actual transfer took place and in which year the brothers came into possession of the County of Vianden cannot be stated with certainty and reliability.

[4][17] John was invested with the Duchy of Cleves and the County of Mark by Roman King Sigismund in 1422, but settled for financial compensation two years later.

In a later treaty of 1429 or 1439, they jointly ceded their rights to the heerlijkheden of Ravenstein, Herpen and Uden to the Counts of Virneburg for a sum of 21,000 gold guilders.

[11] John was also able to the acquire the serfs in Siegerland, which had belonged to the extinct lords of Wildenburg and were fully secured against the rightful heirs, the lords of Hatzfeld; to renew the fiefs over Greifenstein; to get the confirmation of the fiefs of the Electorate of Trier; and to reach a settlement with the Electorate of Mainz after a feud over the part of the toll in Oberlahnstein.

[4] In the last years of his life, which he lived to a high age, John seems to have taken little interest in the affairs of government, preferring to leave them to his nephews, the sons of Engelbert I.

[4] John died unmarried at Dillenburg Castle in early May 1443[4][11][20][note 13] and was buried in Keppel Abbey [de] near Hilchenbach.