Guillaume Pelletier was born in 1598 in Brésolette(s), Perche, France, the son of Éloi Pelletier and Françoise Matte (?Mare). Perche, an old French province, founded in 1115, is west of Paris and east of the coastal province of Normandy. Perche no longer exists as a province today - it is part of Lower Normandy. The ancient province of Perche was dismantled into four uneven parts in 1790, when the French Assembly divided France into "Départments." Today, the province of Perche would correspond roughly to the eastern portion of the "départment" of Orne, and is still referred to as a region of France. Approximately 4% of the early Canadian settlers were from the Perche region.

The region of Perche is a quiet countryside where the original Trappist monastery, "La Grande Trappe," is lost in the Perche forest. However, in the 17th century, Perche was an important iron works center, especially in that part of Perche called the "Val de l'Avre," the Avre River Valley.