Hans Kohlhase (c. 1500 – 1540) according to early modern German accounts was a merchant whose grievance against a Saxon nobleman developed into a full-blown feud against the state of Saxony, thus infringing the Eternal Peace of 1495. The campaign culminated in Kohlhase's execution in March 1540.
In October 1532, according to the story, Kohlhase was proceeding from his hometown of Cölln to the fair at Leipzig, when he was attacked and his horses were taken from him by the servants of a Saxon nobleman, one Günter von Zaschwitz. In consequence of the delay the merchant suffered some loss of business at the fair and on his return he refused to pay the rather large sum which Zaschwitz demanded as a condition of returning the horses. In return Kohlhase asked for a substantial amount of money as compensation for his loss, and failing to secure this he invoked the aid of his sovereign, the Elector of Brandenburg Joachim I Nestor. Finding however that it was impossible to recover his horses, he paid Zaschwitz the sum required for them, but reserved to himself the right to take further action.
Unable to obtain redress in the courts of law, Kohlhase in a feud letter threw down a challenge, not only to his aggressor, but to the whole of Saxony. Acts of lawlessness were soon attributed to him, and after an attempt to settle the feud had failed, the elector of Saxony, John Frederick I, set a price upon the head of the angry merchant. Kohlhase now sought revenge in earnest. Gathering around him a band of criminals and desperados, he spread terror throughout the whole of Saxony; travellers were robbed, villages were burned and towns were plundered. For some time the authorities were practically powerless to stop these outrages, but in March 1540 Kohlhase and his principal associate, Georg Nagelschmidt, were seized, and on the 22nd of the month they were broken on the wheel in Berlin.
Heinrich von Kleist's novel, Michael Kohlhaas, is loosely based on Kohlhase's life. The novel was made into 3 films, Michael Kohlhaas – der Rebell in 1969, and Age of Uprising: The Legend of Michael Kohlhaas in 2013. Further, it was the inspiration for the character Coalhouse Walker, Jr. in E. L. Doctorow's novel Ragtime. And the Jack Bull in 1999.