Rivalry amongst the respective heirs, prefect Egbert of Groningen and burgrave Rudolf II of Coevorden led to conflicts between Drenthe and Groningen in which  the Drenths fought both with and against the troops of the bishop. This came to a head in the Battle of Ane.
Egbert of Groningen and Rudolf II of Coevorden, who were competing for power, initiated conflicts between Drenthe and Groningen where the Drenths fought against various parties. This culminated in the Battle of Ane.