The Battle of Grolle (Dutch: Slag om Grolle) is a regular historical reenactment of the siege of the fortified border town of Groenlo (formerly known as Grol or Grolle) in the Achterhoek in 1627 during the Dutch Revolt. It is held in and around Groenlo itself every two years. The event lasts for three days and features a historic battle reenactment and a historic fair, with reenactors from many European countries.