Count John I of Nassau-SiegenIn many sources he is called John I of Nassau(-Dillenburg). His official title was Count of Nassau, but it is incorrect to refer to him as the only reigning Count of Nassau, because the County of Nassau was divided into Nassau-Beilstein, Nassau-Hadamar, Nassau-Siegen, Nassau-Weilburg and Nassau-Wiesbaden-Idstein. John ruled the County of Nassau-Siegen, which is erroneously called Nassau-Dillenburg in many sources. See note 2. ( – 4 September 1416), , was since 1362 Count of Nassau-SiegenThe County of Nassau-Siegen is erroneously called Nassau-Dillenburg in many sources. The county was not named after the small, unimportant city of Dillenburg, which did not even have a church at that time, but after the, for that time, large city of Siegen, the economic centre of the county and the counts' main residence. See Lück (1981), passim. It is also evident from the numbering of the reigning counts with the given name John. One John without regal number who ruled the County of Nassau-Dillenburg in the period 1303–1328, and eight counts by the name of John who ruled the County of Nassau-Siegen in the period 1362–1638. (a part of the County of Nassau). He descended from the Ottonian Line of the House of Nassau.
John was involved in numerous feuds throughout his life. The chivalric spirit of that time created a multitude of unions and alliances. John was a co-founder or at least an active member of several of these alliances, always ready for quarrels and knightly combat.Joachim (1881), p. 250. 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.Lück (1981), p. 23. 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.Hoffmann (1842), p. 134.
During his long, mostly restless reign, he not only made lucrative acquisitions of various kinds, but also expanded the possessions of his house, most notable through the succession dispute over the County of Nassau-Hadamar.Huberty, et al. (1981), p. 219.Joachim (1881), p. 251.von Stramberg (1865), p. 718. John amply compensated the losses his unfortunate father had inflicted by overcoming great obstacles.Hoffmann (1842), p. 135.
Biography John was born Dek (1970), p. 66.Vorsterman van Oyen (1882), p. 90 and Joachim (1881), p. 250 state born . von Stramberg (1865), p. 712 and Hoffmann (1842), p. 134 state born in 1339 or 1340. as the eldest son of Count Otto II of Nassau-Siegen and Countess Adelaide of Vianden.Vorsterman van Oyen (1882), p. 90.von Stramberg (1865), p. 712.
When John's father was killed in action between 6 December 1350 and 25 January 1351,von Stramberg (1865), p. 711. John succeeded him as Count of Nassau-Siegen. As John was still a minor, his mother assumed regency over the county.Becker (1983), p. 12.Lück (1981), p. 22. This clever and energetic woman, endeavoured to gradually settle the numerous feuds inherited by her and her son with the local noble families, the powerful lords of , Walderdorff and , although she herself did not disdain to take up the gauntlet forced upon her on one occasion or another. On the other hand, she also resolved many of the pledges entered into by her husband. In the underdeveloped County of Nassau-Siegen, where the local nobility thought they had a free hand, she kept the reins tight. She did have to pledge land to clear her husband's debts, and although ending her husband's numerous feuds was not without sacrifice, these agreements brought her the peace for undisturbed reconstruction. The unfinished feuds and frequent interference from the country's resident powerful nobility forced her to make new debts. In 1356, she was forced to conclude a protection alliance with Landgrave Henry II the Iron of Hesse, opening all Nassau castles to the landgrave, during John's minority.
In the district of Haiger, the noble family of the same name had been very powerful from old times. Under the favour of its feudal lords, it resisted the overlordship of the Counts of Nassau. John's minority seemed to be the most opportune time for it to shake off this yoke completely. Heiderich von Haiger's arrogance went so far that he allowed himself to commit abuses against the person of the young John. An open feud ensued, the ruinous consequences of which, as usual, affected the countryside and its inhabitants. 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.von Stramberg (1865), p. 713. The conflict with sword and lance was followed by a legal dispute, before a settlement was concluded in 1357 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. The pledge of the parish of Haiger and half of Ginsburg Castle was undone. It decided the struggle with the lords of Haiger for supremacy in the Mark Haiger in favour of the Nassaus. The lords of Haiger became vassals of the Nassaus.Becker (1983), p. 14. The beneficial consequences of peace and tranquillity became apparent in the next few years.
From 1359 to 1362, Adelaide and John redeemed the most considerable pledges. Because of 3200 pounds Heller and 2000 shield guilders, which Holy Roman Emperor Charles IV owed the deceased Count Otto, he assigned old large tornesel from some water or land tolls. Often to such grants this clause was added: 'when he may acquire it at a prince's or lord's tolls'. If an agreement was reached with the owner of the toll, the toll's duty was increased in proportion to the sum granted, which, of course, should only have been temporary in accordance with the intention, but which may have given rise to many a continuing increase in toll's duty that was detrimental to trade.von Stramberg (1865), pp. 713–714. 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,von Stramberg (1865), p. 714. 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. As usual, a feud ensued. In the autumn of 1362, Archbishop , 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. In December of the same year, Gerlach and John signed a peace treaty at Aschaffenburg. Gerlach promised to pay 3500 florins and to grant John a tornesel from the toll at Oberlahnstein until he would have drawn 2000 florins from it. Later, a new dispute arose over this toll, which was only settled in 1407 to the effect that John should be allowed a tornesel from the toll for life.
John took over the reign in 1362. He immediately started a feud with Godfrey of Heinsberg over John's claims to the Lordship of Heinsberg and , originating from the marriage of his grandfather Count Henry I of Nassau-Siegen to Lady , which Godfrey had partly transferred to his brother-in-law, Duke William I of Jülich. The feud was eventually sufficiently resolved by the assurance of monetary payments in 1363 and 1374.
John joined the , a knights alliance. This alliance was founded following the death of Landgrave Otto the Younger of Hesse in 1366. As the only son of the old Landgrave Henry II the Iron, Otto had taken a most active part in the government for several years. Now Landgrave Henry appointed his brother's son Herman the Younger as co-regent and successor. Henry's grandson, Duke Otto I of Brunswick-Göttingen, who had also hoped for this succession, was very dissatisfied with his grandfather's choice. The Hessian nobility, who, like the nobility elsewhere, always knew how to profit from internal unrest, was largely averse to the new ruler because of the reforms introduced and the abolition of abuses that had crept in. Rarely did any of the neighbours remain on good terms with each other longer than during a joint feud against a third. In this case, Landgrave Henry was also exposed to the jealousy of most of his neighbours. In these circumstances, it was not difficult for Duke Otto to find a large number of participants in his dispute with his grandfather and his co-ruler. Count presented himself as the leader of the allies. From the coat of arms of the County of Ziegenhain, the allies took the silver star as their field emblem, from which they received the name Sterners. The allies included, among others, the counts Engelbert III of the Mark, Henry VI of Waldeck, Diether VIII and , the lords Ulrich IV of Hanau, of Epstein, and several of the nobility and lords of Westphalia, Hesse, Franconia, the Wetterau and by the Rhine. The inclination towards war of Count John I of Nassau-Siegen alone would have made this opportunity to satisfy it desirable to him. 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.von Stramberg (1865), p. 715. Furthermore, Landgrave Henry had obtained the feudal lordship over Driedorf in 1348 and now, after the death of Count , took occasion from the idiocy of Count to treat this district as an open fief and to seize a part of it for himself.von Stramberg (1865), pp. 715–716. There was also a dispute between them about the of Nassau, a fief acquired by purchase by Hesse, and which John wanted to obtain as forfeited.von Stramberg (1865), p. 716.
In another feud, against Lord John of Westerburg, John was captured with 44 horsemen near in 1370 and only released after paying a ransom of 10,000 guilders. Both parties remained at peace until 1408, when the renewal of hostilities interrupted the friendly understanding for a while. In 1371 John fought in the Battle of Baesweiler on the side of Duke William II of Jülich and Duke Edward of Guelders against Duke Wenceslaus I of Luxembourg and Duchess Joanne of Brabant.von Stramberg (1865), p. 721. Meanwhile, the war with Hesse lasted until around 1373 and was conducted according to the custom of the time. The Sterners invaded Hesse several times, devastated and plundered as much as they could and then retreated with the booty to their castles. In all this, the first and main purpose of the Sternerbund was not achieved. Landgrave Herman remained in possession of the co-regency and was Landgrave Henry's only successor after his death. John achieved just as little of his original intention. The Sterners were unable to assert his right to Driedorf.