Tags: Noble.
Count Jan (Johann) IV of Nassau (1 August 1410 Dillenburg – 3 February 1475 Breda) was Count of Nassau Dietz and Dillenburg. He was the son of Engelbert I of Nassau Count of Nassau and Dillenburg Lord of Breda and Johanna van Polanen. He married Maria Countess of Loon and Heinsberg Lady of Millen Gangelt and Vucht (born in 1424) the daughter of John VIII of Heinsberg on 7 February 1440.