Pier Gerlofs was born around 1480 in Kimswerd near the city of Harlingen, Wonseradeel (modern Friesland, Netherlands). Pier Gerlofs was one of at least four children born to Fokel Sybrants Bonga and Gerlof Piers. Pier's mother Fokel was the daughter of the Schieringer noblemen Sybrant Doytsesz. Bonga of Bongastate, Kimswerd.
Pier married Rintsje Syrtsema and they had two children, a son named Gerlof and a daughter named Wobbel, who were born around 1510. Pier died in 1520, and in 1525, Pier's mother appointed in her will Pier's brother, Sybren, as guardian of Pier's children, who still were minors. Pier and Pier's brother-in-law Ane Pijbes (husband of Tijdt Gerlofs), were partners in the farming estate of Meyllemastate in Kimswerd.
Wijerd Jelckama often is described by 18th and 19th century authors as the nephew of Grutte Pier. Contemporary Worp van Thabor identifies him simply as Wierd van Bolsward. Modern authors such as J.J. Kalma doubt the nephew connection and Brouwer in the Encyclopedia of Friesland states that Wierd was not Grutte Pier's nephew but instead his "lieutenant".
Approximately 7 kilometres (4.3 mi) to the north-east of Donia's village of Kimswerd, in the city of Franeker, the Black Band, a Landsknecht regiment in the service of George, Duke of Saxony was quartered. The regiment was charged with suppressing the civil war between the Vetkopers, who opposed Burgundian and subsequently Habsburg rule, and the Schieringers. The Black Band were notorious as a violent military force; when their pay was insufficient or lacking, they would extract payments from local villagers and on 29 January 1515, the Black Band plundered Donia's village, then allegedly raped and killed his wife, Rintze Syrtsema, and burnt to the ground both the village church and Donia's estate. Seeking revenge, Pier started a guerrilla war campaign against the Habsburgs and allied himself with Charles of Egmond, Duke of Guelders (1492–1538).