The Battle of Kutná Hora (Kuttenberg) was an early battle and subsequent campaign in the Hussite Wars, fought on 21 December 1421 between German and Hungarian troops of the Holy Roman Empire and the Hussites, an early ecclesiastical reformist group that was founded in what is now the Czech Republic. In 1419, Pope Martin V declared a crusade against the Hussites. One branch of the Hussites, known as the Taborites, formed a religious-military community at Tábor. Under the leadership of the talented general Jan Žižka, the Taborites adopted the latest weaponry available, including handguns, long, thin cannons, nicknamed "snakes", and war wagons. Their adoption of the latter gave them the ability to fight a flexible and mobile style of warfare. Originally employed as a measure of last resort, its effectiveness against the royal cavalry turned field artillery into firm part of Hussite armies.