The text was written somewhere between 1568 and 1572, in honour of William of Orange (also known as William of Nassau), during the Dutch revolt against the Spaniards, the Eighty Years War. The author was probably Marnix van St. Aldegonde.
When The Netherlands became a kingdom in 1815, the song was not chosen as its national anthem, because it was too connected to the party that supported the House of Orange-Nassau. However its popularity never waned, and in 1932 it became the national anthem after all.
This is the first stanza, modernized a great deal:
Wilhelmus van Nassouwe Ben ik van Duytschsen bloedt Den vaderland ghetrouwe Blijf ik tot in de dood Een Prins van Oranje Ben ik vrij onverveerd Den Koning van Hispanje Heb ik altijd gheeŽrdTo give a translation of this stanza is hard, because almost every line has several possible interpretations. Unfortunately, the author is no longer around to fill us in on what he meant.
Anyhow, a hopefully not too contestable try:
William of Nassau, I am, of Germanic descent True to the fatherland I remain until death A Prince of Orange Am I, free and fearless To The king of Spain I have given a lifelong loyalty(The last two lines are often interpreted to mean that the leader of the Dutch war against Spain had no specific qualms with the king, but rather with his emissaries in the Low Countries; it may also be sheer sarcasm. "Duytschen" (German) in the text refers not to Germany or the German people, but rather at the time this song was written still referred to the Netherlands and the Dutch people. See Diets.)
Usually only the first stanza is sung. When another stanza is sung, it is usually the sixth:
Mijn schild ende betrouwen zijt Gij, o God mijn Heer op U zo wil ik bouwen Verlaat mij nimmermeer Dat ik doch vroom mag blijven uw dienaar t'aller stond de tirannie verdrijven die mij mijn hart doorwondtAn English translation of the sixth stanza can be found through clicking on the third link below.
The anthem is an acrostic, which in this case means the first letters of the fifteen stanzas form the name 'Willem van Nassav' (van means 'of' or, as in this case, 'from').