Pier Gerlofs Donia was a Frisian rebel leader and pirate. He is best known by his West Frisian nickname Grutte Pier , or by the Dutch translation Grote Pier which referred to his legendary size and strength.
His life is mostly shrouded in legend. Based upon a description now attributed to Pier's contemporary Petrus Thaborita, the 19th-century historian Conrad Busken Huet wrote that Grutte Pier was
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“Butter, bread, and green cheese: whoever cannot say that is not a true Frisian.”
Quoted in: The Linguist: Journal of the Institute of Linguists. Volumes 42-43, The Institute, 2003. p. 192
According to legend, Pier forced his captives to repeat this shibboleth to distinguish Frisians from Dutch and Low Germans.
