The origins of the lyrics are uncertain. "Wilhelmus" was first written some time between the start of the Eighty Years' War in April 1568 and the Capture of Brielle on 1 April 1572, making it at least years old. Soon after the anthem was finished it was said that either Philips of Marnix, a writer, statesman and former mayor of Antwerp, or Dirck Coornhert, a politician and theologian, wrote the lyrics. However, this is disputed as neither Marnix nor Coornhert ever mentioned that they had written the lyrics, even though the song was immensely popular in their time. "Wilhelmus" also has some odd rhymes in it. In some cases the vowels of certain words were altered to allow them to rhyme with other words. Some see this as evidence that neither Marnix or Coornhert wrote the anthem, as they were both experienced poets when "Wilhelmus" was written, and it is said they would not have taken these small liberties. Hence some believe that the lyrics of the Dutch national anthem were the creation of someone who just wrote one poem for the occasion and then disappeared from history. A French translation of "Wilhelmus" appeared around 1582.