|Birth||1 January 1426|
|Death||20 April 1502|
Maria of Loon-Heinsberg (1426 – 20 April 1502) was the daughter of John II of Loon, Lord of Jülich, Heinsberg and Löwenberg. Her mother was the second wife of John II, Countess Margaret of Solms-Braunfels.
Maria died on 20 April 1502 as the last member of the house of Loon-Heinsberg and is buried with her husband in the mausoleum of Engelbert I of Nassau in the Church of Our Lady at the Market Square in Breda.
Marriage and issue
She married on 7 February 1440 with John IV, Count of Nassau, Lord of Breda. They had the following children:
- Anna (c. 1441 – 1514), married:
- in 1467 with Otto V, Duke of Brunswick-Lüneburg (c. 1439-1471)
- in 1474 with Philip I, Count of Katzenelnbogen
- Johanna (c. 1444 – c. 1468), married in 1467 with Philip I, Count of Waldeck
- Odilia (c. 1445 – 1493)
- Adriana (1449–1477), married in 1468 with Philip I, Count of Hanau-Münzenberg
- Engelbert II (1451–1504), married in 1468 with Cimburga of Baden
- John V (1455–1516), married in 1482 with Elisabeth of Hesse-Marburg (1466–1523)