Where does the name Orange-Nassau come from?

The ties between the House of Nassau, later the House of Orange-Nassau, date from 1403, when the German Count Engelbrecht I of Nassau married Johanna van Polanen, a wealthy Dutch heiress. The Nassaus settled in Breda and soon became one of the leading noble families in the Low Countries. When Count Hendrik III of Nassau (1483-1538) married Claudia de Chalon, lands in the east and south of France were added to the Nassau family fortune. They included the sovereign principality of Orange, which carried the hereditary title of Prince of Orange. When Hendrik’s son René de Chalon died childless in 1544, his eldest cousin William of Nassau (1533-1584) inherited his property and the title Prince of Orange. This William of Nassau, known as William of Orange or William the Silent, is regarded as the founder of the House of Orange-Nassau.