Mary was known as a very devout Catholic.[6][7][14] At the initiative of Mary and John the Sacrament of Niervaert[nl] was transferred to the Grote Kerk in Breda in 1449. This was a miraculous host whose history is told in the Middle DutchplaySpel vanden heilighen sacramente vander Nyeuwervaert[nl] and which is also depicted on the Retable of the Sacrament of Niervaert[nl] from around 1535.[7]
After the death of his brother in 1451, John inherited his brother's possessions.[1][6][10][15][16][20] His widespread possessions forced John to travel constantly, in order to govern his possessions well. When John was in his county, he governed it from Siegen or Dillenburg.[21] When the count's family started staying in the county more often, a court was established.[22] John had Dillenburg Castle –which until then had been used primarily as a stronghold against the unruly local nobility– extended in the period 1453–1467 and rebuilt into a residential castle for the count's family.[23] In 1464 Mary had a church chair made in the castle chapel and a shrine for the Blessed Sacrament.[24]
In 1469 Mary sent for rosemary and other herbs to be brought to Dillenburg from the Rhine (Cologne or Koblenz), presumably because of the plague. This is the oldest surviving report in the accounts about medicines.[25]
Through the marriage to Mary, John obtained the heerlijkheden of Herstal, Vught, Gangelt, Waldfeucht and the Land of Millen[de], so that he possessed ¼ of the Duchy of Jülich.[20][21][note 5] This led to a dispute with John's distant relative Count John II of Nassau-Saarbrücken, who was married to Lady Jeanne of Looz-Heinsberg, the daughter and heiress of Lord John IV of Looz-Heinsberg.[26] At Mary's husband's request, EmperorFrederickIII declared on 28May 1470 that by granting the entire Duchy of Jülich to Duke GerhardVII, the claims of Mary and her sister Philippa of Looz-Heinsberg, were not to be affected.[27] Apparently this had no effect, because in 1471 or 1472 the Emperor ordered DukeCharles the Bold of Burgundy to settle on his behalf the dispute between Gerhard on the one hand and Mary and John on the other.[28] The dispute became more complicated when in 1472 GerhardVII's son William married to Countess Elisabeth of Nassau-Saarbrücken, JohnII's eldest daughter, who had inherited her mother's possessions.[26][29][30] In 1474, the Emperor withdrew the order to Charles the Bold and instead transferred the matter to ArchbishopJohnII of Trier.[31] The dispute was only settled when on 25August 1499 Mary's eldest son EngelbertII transferred his half of the castle and the land of Millen with the towns of Gangelt and Vught to Duke William of Jülich and Berg and received in exchange from the latter on 27August 1499 the city and the land of Diest and the castle and the land of Zichem and Zeelhem.[30][32]
As a widow Mary founded Vredenburg Abbey in Bavel in 1476,[2][5][6][7][14] and the convent of the Grey Sisters[nl] in 1478.[6] She also devoted herself to the nunnery Saint Catherinadal Abbey in Breda.[6][7] And in 1486 she generously endowed Saint Wendelin's chapel in Breda.[14]
Mary stipulated in her will and testament, drawn up in 1501, that the Rentmeister[de] should distribute 100 malters[de] of grain from her estate for the poor of Dillenburg.[33] She died in Siegen[34] on 20April 1502[1][2][3][4][34] and was buried in the Grote Kerk in Breda.[35][36][note 6]
The Grote Kerk in Breda, 2012.
The epitaph for EngelbertI of Nassau-Siegen, Joanne of Polanen, JohnIV of Nassau-Siegen and Mary of Looz-Heinsberg, in the Grote Kerk in Breda. Photo: Richard Broekhuijzen, 2017.
From the marriage of Mary and John the following children were born:[37][38][39][note 7]
Ottilie (c.1445[note 12] – Alkmaar, 22April 1495). Was a nun in the Bethany Abbey near Mechelen until 1463 and then in the Saint Catherinadal Abbey in Breda 1463–1476. She was the first prioress of Vredenburg Abbey in Bavel 1476–1495.
Count EngelbertII the Illustrious (Breda, 17May 1451 – Brussels, 31May 1504), succeeded his father in the possessions in the Netherlands. Married in Koblenz on 19December 1468 to Margravine Cimburga of Baden[nl] (15May 1450 – Breda, 5July 1501).
Count JohnV (Breda, 9November 1455 – Dillenburg or Siegen,[note 14] 30July 1516), succeeded his father in Nassau-Siegen and Diez. Married in Marburg on 11February 1482 to Landgravine Elisabeth of Hesse-Marburg (Marburg, May 1466 – Cologne, 17January 1523[note 15]).
Anne of Nassau-Siegen (1440/41–1514). Anonymous portrait, c.1460.
Ottilie of Nassau-Siegen (c.1445–1495). Portrait by master Sommeren, 1681. Saint Catharinadal Abbey, Oosterhout.
Epitaph of Adriana of Nassau-Siegen (1449–1477). Marienkirche, Hanau. Photo: Reinhard Dietrich, 2009.
Count EngelbertII the Illustrious of Nassau-Breda (1451–1504). Portrait by the Master of Portraits of Princes, 1487. Rijksmuseum, Amsterdam.
More information Ancestors of Mary of Looz-Heinsberg ...
Kremer, Christoph Jacob (1786). Geschichte der Herrn von Heinsberg des jüngern Geschlechts im Herzogthum Gülch. Nebst einigen diplomatischen Nachrichten vom Geschlechte der alten Herrn von Diest (in German). Giessen: Krieger dem jüngern.
In English and French the county her name originated from is called Looz, while in Dutch and German it is called Loon. In older Dutch and German sources one can also find the spelling Loen.
Van Ditzhuyzen (2004), p.151, however, states 1426 as her year of birth. That year of birth is unlikely, as it would mean that she married at the age of thirteen or fourteen, and that she gave birth to her first child at the age of fourteen or fifteen.
Most of the sources do not mention a place of birth. Van Ditzhuyzen (2004), p.151 states Dillenburg as place of birth, but that place of birth is very unlikely as his parents resided in the Netherlands in those days.
Lück (1981), p.25 states that Mary was buried in the St. John's Church of the Franciscan monastery in Siegen, which was founded by her son JohnV. Since Mary is not mentioned in the records of the members of the House of Nassau buried in St. Mary's Church in Siegen –where they were reburied in 1836 from the aforementioned monastery church–, the author probably made a mistake.
The second daughter from this marriage, Joanne, is not mentioned by Vorsterman van Oyen (1882) and Textor von Haiger, Johann (1617). Nassauische Chronik. In welcher des vralt, hochlöblich, vnd weitberühmten Stamms vom Hause Naßaw, Printzen vnd Graven Genealogi oder Stammbaum: deren geburt, leben, heurath, kinder, zu Friden- vnd Kriegszeiten verzichtete sachen und thaten, absterben, und sonst denckwürdige Geschichten. Sampt einer kurtzen general Nassoviae und special Beschreibung der Graf- und Herschaften Naßaw-Catzenelnbogen, etc (in German). Herborn: Christoph Raab.
Katzenelnbogen, Anna Gräfin von states that she was born in Dillenburg. That is very unlikely as her parents resided in Breda at that time according to Van Ditzhuyzen (2004), p.152.
Schutte (1979), p.42, Dek (1970), p.70, and Vorsterman van Oyen (1882), p.95 mention Ottilie as the youngest daughter, without mentioning a date of birth, born after her brother John, who was born in 1455. Ottilie being born after 1455 seems to be unlikely as she was already mentioned as a nun to reform a convent in 1463. The year of birth c.1445 in Ruizendaal, Willem & Conrads, Marian (1995). Nassau & Oranje. 600 jaar geschiedenis van ons vorstenhuis. Van EngelbertI tot Willem-Alexander (in Dutch). Baarn: BV Uitgeversmaatschappij Tirion. p.37. ISBN90-5121-548-7.
Schutte (1979), p.42 and Dek (1970), p.70 state Dillenburg as place of death, and Vorsterman van Oyen (1882), p.95 states Dillenburg Castle. Assman & Menk (1996), however, state Siegen Castle as place of death and Joachim (1881), p.253 states Siegen.
Schwennicke, Detlev (1978–1995). Europäische Stammtafeln. Stammtafeln zur Geschichte der Europäischen Staaten. Neue Folge (in German). Marburg: J.A. Stargardt.
Van der Aa, A.J. (1860). "JanIV, graaf van Nassau, Vianden, Dietz enz.". Biographisch Woordenboek der Nederlanden, bevattende levensbeschrijvingen van zoodanige personen, die zich op eenigerlei wijze in ons vaderland hebben vermaard gemaakt (in Dutch). Vol.Negende deel. Haarlem: J.J.van Brederode. pp.87–88.
Becker, E. (1983) [1950]. Schloss und Stadt Dillenburg. Ein Gang durch ihre Geschichte in Mittelalter und Neuzeit. Zur Gedenkfeier aus Anlaß der Verleihung der Stadtrechte am 20.September 1344 herausgegeben (in German) (Neuauflageed.). Dillenburg: Der Magistrat der Stadt Dillenburg.
Huberty, Michel; Giraud, Alain & Magdelaine, F.&B. (1981). l'Allemagne Dynastique (in French). Vol.Tome III: Brunswick-Nassau-Schwarzbourg. Le Perreux: Alain Giraud. ISBN2-901138-03-9.
Jansen, H.P.H. (1979). "De Bredase Nassaus". In Tamse, C.A. (ed.). Nassau en Oranje in de Nederlandse geschiedenis (in Dutch). Alphen aan den Rijn: A.W.Sijthoff. pp.11–40. ISBN90-218-2447-7.
Lück, Alfred (1981) [1967]. Siegerland und Nederland (in German) (2nded.). Siegen: Siegerländer Heimatverein e.V.
Van Raak, Cees (1995). Heden vredig ontslapen. Funeraire geschiedenis van het huis Oranje-Nassau (in Dutch). Bussum: Uitgeverij Thoth. ISBN90-6868-117-6.
Schutte, O. (1979). "Genealogische gegevens". In Tamse, C.A. (ed.). Nassau en Oranje in de Nederlandse geschiedenis (in Dutch). Alphen aan den Rijn: A.W.Sijthoff. pp.40–44. ISBN90-218-2447-7.
Toebosch, Theo (1996). "Gebalsemde Oranjes". NRC Handelsblad (in Dutch) (published 14 December 1996).
Van der Eycken, Michel (1980). "Diest en het Huis Oranje-Nassau". Diest en het Huis Oranje-Nassau. Diestsche Cronycke (in Dutch). Vol.3. Diest: Stedelijk Museum. pp.15–42.
Vorsterman van Oyen, A.A. (1882). Het vorstenhuis Oranje-Nassau. Van de vroegste tijden tot heden (in Dutch). Leiden & Utrecht: A.W.Sijthoff & J.L.Beijers.
De Vries Feyens, G.L. (1933). "De voorouders van den Prins van Oranje op Nederlandschen bodem". In De Savornin Lohman, Jhr. B.C.; De Vries Feyens, G.L.; Beelaerts van Blokland, Jhr. W.A.; Goosens, Th.J.A.J.; Van Schelven, A.A. & Theissen, J.S. (eds.). Prins Willem van Oranje 1533-1933 (in Dutch). Haarlem: H.D.Tjeenk Willink & Zoon N.V. pp.11–24.