[1] During the 11th century, the Lords of Erguel, or Arguel, moved from Franche-Comté and settled in the village of Sonvilier.

[2] Exactly when they built Erguel Castle on a hill south-east of the village is unknown, but in 1178 and 1184 Heinrich von Erguël was mentioned ruling over the region.

[1] The knights of Erguel owned land in the surrounding valley and held the vogt office over the church at Saint-Imier.

In 1617 Bishop Wilhelm Rinck of Baldenstein repaired the castle and stationed a garrison there to protect his land against the city of Biel.

However, the lease contained the condition that the dilapidated building must be well maintained and they were unable to find a tenant.

[1] The castle is a long, narrow structure that runs east-west on an exposed hilltop south of Sonvilier.