The Chanson de Chartres would be the (first) melody of the national anthem. This anthem is considered as the oldest in the world.
When the national anthem was adopted in 1932, the official anthem of the Netherlands, it was thought that the nobleman Marnix van Sint Aldegonde (mayor of Antwerp) was its author. He was around 1570 befriended with circles around the House of Orange. The problem is that no single link ever found between Marnix and Chartres.
Computer programs that the word usage and writing style to explore a variety of texts to compare texts from unknown authors to date texts by famous authors and a suspected writer to provide, now indicate (2016) Peter Datheen as presumed author. Peter Datheen, preacher and poet of the 16th century, was present at the siege of Chartres in 1568, when that song came. So he knew the opposition song: Chanson de Chartres and also had the skills to write the text. He also made a famous ancient metrical psalms. In the picture: Peter Datheen.
It is seen by most Dutch as “their” anthem not that of the government. So it has several versions. Even a German by the Germans those imposed in WWII. The latter was and is, of course, by most Dutch, vehemently rejected. In modern times, there is grew even a “disco” version.