[1] Through negotiations, and when necessary also through skilfully conducted feuds, he secured his country many kinds of benefits, for example income from old, hitherto little-used Rhine tolls.

[2] In this way, the courageous count not only kept his father's inheritance unbroken and even debt-free during difficult times and a long life, but also triumphed over his opponents, who wanted to shorten and challenge it, sometimes in the open field, sometimes before courts of arbitration.

[3] During his long, mostly restless reign, he not only made lucrative acquisitions of various kinds, but also expanded the possessions of his house,[3] most notable through the succession dispute over the County of Nassau-Hadamar.

[7] John was born c. 1339[8][note 3] as the eldest son of Count Otto II of Nassau-Siegen and Countess Adelaide of Vianden.

Adelaide, however, did not lack courage and steadfastness to counter the insolence and violence of her enemies with vigour and to defend the rights of her son.

There is no doubt that she benefited greatly from the support of her allies, Landgrave Henry II the Iron of Hesse and his son Otto the Younger.

[14] The conflict with sword and lance was followed by a legal dispute, before a settlement was concluded in 1357[3][14] by Count Thierry III of Looz, the chairman of the court, in a decision written in 63 articles, which is a most remarkable explanation of the customs and rights of that age.

[3][14] Because of 3200 pounds Heller and 2000 shield guilders, which Holy Roman Emperor Charles IV owed the deceased Count Otto, he assigned 1½ old large tornesel from some water or land tolls.

[16] Adelaide and her son, as it seems, sought satisfaction for the aforementioned debt of Emperor Charles IV to the toll of the Electorate of Mainz at Oberlahnstein,[3][17] which was closest to them.

In any case, they had even older claims on the Electorate of Mainz, probably dating back to Roman King Louis IV's time.

In the autumn of 1362, Archbishop Gerlach [de],[note 4] invaded Nassau-Siegen with 500 horsemen, each of whom, according to the custom of the time, were accompanied by a few armed footmen.

The long known belligerent peasants of the Rheingau scorched, looted and devastated the county, but had to retreat across the Rhine when the floods came, to prevent being cut off.

He had also been an enemy of Landgrave Henry from earlier years, and might now consider it the best time to avenge the damage that the Hessians had inflicted on the Siegerland in the Hatzfeld feud around 1360.

[21] There was also a dispute between them about the Lordship of Itter [de] of Nassau, a fief acquired by purchase by Hesse, and which John wanted to obtain as forfeited.

The settlement of 1378 at least proves that he had regained possession of this castle and district, although there are no definite records of when this happened and how Driedorf was returned to Hesse after 1378.

Finally, under the mediation of the Hoch- und Deutschmeister Johann von Hayn and the counts of Katzenelnbogen and Sponheim, a provisional settlement was reached in Friedberg in 1377.

Landgrave Herman, however, did not want to settle down with this decision, but nevertheless promised to give John a hearing before his knights and men on the matter of Driedorf and Itter.

As early as 1379, John joined a new alliance against Hesse, which was established in the Wetterau under the name of the Gesellschaft mit dem Löwen (Society with the Lions).

John also seems to have been a member of a Gesellschaft mit den Hörnern (Society with the Horns), which was also established around this time with the purpose of mutual defence and assistance.

[25] However, Charles IV's son and successor, Roman King Wenceslaus, enfeoffed him with Arnsberg in Nuremberg in 1379,[2][5][25] as a county that had rightfully and honestly accrued to him.

What is certain, is that from 1392 onwards John granted his vassals, the Lords of Rennenberg [de], the right to fly this storm flag in the event that he did not go into the field in person.

Probably through William's mediation, the English royal decrees came about that allowed Siegen's citizens to trade in England undisturbed and with many privileges, and to live according to their own morals and customs.

In addition, Adolf was to receive the dowers belonging to his grandmother Adelaide of Vianden (the Herbermark and the parish of Haiger), as well as half of castle, city and district of Löhnberg, but only until he came into full possession of the Nassau-Hadamar inheritance.

If Gerhard were to die without leaving any sons, his daughter's marriage to Adolf would be consummated immediately and the entire County of Diez would pass to him.

John had to seek dispensation from the Pope for this marriage, because the betrothed were related in the fourth degree, great-grandchildren of the brothers Henry I of Nassau-Siegen and Emicho I of Nassau-Hadamar.

[23] Finally, John III recognised his county as an old Nassau fief[2][5][15][23] and promised to be enfeoffed with the same and all his castles, towns, districts, villages and subjects by Nassau-Siegen for himself and his descendants at any time.

[23] John sometimes had to endure attacks and abuse from his younger brother, Henry the Swashbuckler, who, even though he was a canon, nevertheless was a brutal fighter of his time, as the disconcerting epithet that his comrades gave him reveals.

[3][5] John obtained ⅓ of Hadamar and Ellar Castle [de], ⅔ of (Bad) Ems,[note 7] the Esterau and Dietkirchen.

[33] 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.