Philip van Marnix, lord of Sint-Aldegonde, West-Souburg, etc., was a South Netherlandish writer, diplomat, scholar and adviser to William of Orange. Marnix was mayor of Antwerp during the siege and fall of Antwerp in 1585. He is also mentioned as the author of the Wilhelmus, the Dutch national anthem. However, whether he is actually the author is not certain.
St. Aldegonde, or Marnix, is celebrated for his share in the great development of Dutch literature which followed the classical period represented by such writers as the poet and historian Pieter Hooft. Of his works, the best known is the Roman Bee-hive, published in 1569 during his exile in Friesland, a bitter satire on the faith and practices of the Roman Catholic Church. This was translated, or adapted, in French, German and English. He also wrote an educational treatise dedicated to John, Count of Nassau. As a poet, St. Aldegonde is mainly known through his metrical translation of the Psalms; and, the Dutch national anthem Wilhelmus van Nassouwe is also ascribed to him. His complete works, edited by Lacroix and Quinet, were published at Brussels in 7 volumes (1855–1859), and his religious and theological writings, edited by Van Toorenenbergen, at The Hague, in 4 volumes (1871–1891).