Kulm law, Culm law or Cheà Âmno Law (; ; ) was a legal constitution for a municipal form of government used in several Central European cities in the Middle Ages and early modern period.
It was initiated on 28 December 1233 in the Monastic State of the Teutonic Knights by Grand Master Hermann von Salza and Hermann Balk when the towns of Toruà  (Thorn) and Cheà Âmno (Kulm) received German town law, in particular as a modification of Magdeburg rights. Named after the town it was signed in, the original document (Kulmer Handfeste) was lost in 1244 when the town hall burned due to an attack by à ÂwiÃÂtopeà Âk II, Duke of Pomerania. The renewed charter of 1 October 1251 was based on a copy in Toruà Â, but the rights were reduced. The town hall in Cheà Âmno was the seat of the higher court of Cheà Âmno law until 1458.
This type of law was mostly granted by the Teutonic Order to cities within their monastic state, and by the neighboring Duchy of Masovia, but also elsewhere in Poland and Lithuania. The law introduced a number of advantages for residents over Magdeburg rights, including the right to elect the local judge, and the right of inheritance by descendants of both genders. From the 13th to the 18th century, at least 224 towns were vested with the law. In addition, the Kulm law was expanded, independently from the Knights, to a larger set of laws called Alter Kulm.
During World War II the charter of 1251 was stolen by the German occupiers from the Old Town City Hall in Toruà Â, but was restored to Poland after the war. It is held in the State Archive in Toruà  since 1959. It is listed on the Polish National List of the Memory of the World Register, which includes candidates for the international register.
Cities located under Cheà Âmno Law are currently mostly located in northern and central Poland, in the regions of Dobrzyà  Land, Krajna, Kuyavia, Masuria, Mazovia, Podlachia, Pomerania, Powià Âle, Warmia, with some in southern Poland (Lesser Poland), and in Lithuania and Russia (Kaliningrad Oblast). The largest are Polish capital Warsaw, major cities on the Vistula River Pà Âock, Toruà  and Grudziàdz, major port cities of Gdaà Âsk, Kaliningrad and KlaipÃÂda, plus Olsztyn.
The historic centers of Toruà  and Warsaw are listed as UNESCO World Heritage Sites, with the historic centers of Cheà Âmno, Gdaà Âsk and Tykocin, and major landmarks of Czerwià Âsk nad Wisà ÂÃÂ, Grudziàdz, Kwidzyn, Lidzbark Warmià Âski, Malbork, Olsztyn, Pà Âock and Puà Âtusk additionally listed as Historic Monuments of Poland.
Cities include:
Cities and towns for which it was a replacement of a previous municipal charter in italics.