The Cheà Âmno Voivodeship () was a unit of administrative division and local government in the Kingdom of Poland since 1454/1466 until the Partitions of Poland in 1772/1793. Its capital was at Cheà Âmno.
Together with the Pomeranian and Malbork Voivodeships and the Prince-Bishopric of Warmia it formed the province of Royal Prussia, and with several other voivodeships it formed the Greater Poland Province.
The Cheà Âmno Land had been part of the Polish Duchy of Masovia since 1138. It was occupied by pagan Old Prussian tribes in 1216, who struggled against their Christianization instigated by Bishop Christian of Oliva. After several unsuccessful attempts to reconquer Cheà Âmno, Duke Konrad I of Masovia in 1226 called for support by the Teutonic Knights, who indeed approached and started a Prussian campaign, after the duke promised to grant the Cheà Âmno Land as a fief to the Teutonic Order.
In the course of the Order's decline after the 1410 Battle of Grunwald, the citizens of Cheà Âmno, Toruà  (Thorn), Lubawa (Löbau), Brodnica, Grudziàdz, Nowe Miasto and Radzyà  co-formed the anti-Teutonic Prussian Confederation. In 1454, the organisation led an uprising against the rule of the Teutonic Knights, and asked King Casimir IV of Poland to reincorporate the region to the Kingdom of Poland, to which the King agreed and signed the act of reincorporation, which sparked the Thirteen Years' War between the Knights and the Kingdom of Poland. The towns and nobles of the region then took an oath of allegiance to Poland in Toruà  on 28 May 1454. The Cheà Âmno Voivodeship was established the same year. After the Order's defeat, the reintegration of Cheà Âmno Land with Poland was confirmed in the Second Peace of Thorn and together with the adjacent Lubawa Land in the east it formed the Cheà Âmno Voivodeship of the Kingdom of Poland, since the 1569 Union of Lublin part of the PolishâÂÂLithuanian Commonwealth.
The voivodeship was annexed by Prussia during the First Partition of Poland in 1772, except for the city of Toruà Â, which was not incorporated into the province of West Prussia until the 1793 Second Partition.
Voivodeship Governor (Wojewoda) seat:
Regional council (sejmik generalny)
Regional councils (sejmik poselski i deputacki)
Administrative division:
The largest city of the voivodeship was the royal city of Toruà Â, which as one of the largest and most influential cities of entire Poland enjoyed voting rights during the Royal free elections. It was the birthplace of the renowned astronomer Nicolaus Copernicus in 1473, and place of death of Polish King John I Albert in 1501. It was the location of the Sejm of the PolishâÂÂLithuanian Commonwealth (parliament) in 1576 and 1626, and the Colloquium Charitativum, a three-month congress of European Catholics, Lutherans, and Calvinists, considered an important event in the history of interreligious dialogue, held in 1645 on the initiative of King Wà Âadysà Âaw IV Vasa at a time when religious conflicts occurred in many other European countries and the disastrous Thirty Years' War was fought west of Poland.
Other royal cities and towns were Brodnica, Golub, Grudziàdz, Kowalewo, Lidzbark, à Âasin, Nowe Miasto, Radzyà Â, Rogoà ºno, whereas private church towns were Cheà Âmno, Cheà Âmà ¼a, KurzÃÂtnik, Lubawa and Wàbrzeà ºno. In 1750, also Ostromecko was granted town rights, which, however, it was deprived of shortly after its annexation by Prussia in the First Partition of Poland.
The most prominent educational institutions of the province were the Academic Gymnasium in Toruà Â, founded in 1594 from a former municipal school, and the Cheà Âmno Academy in Cheà Âmno, transformed from a local gymnasium in 1692, which in 1756 became a branch of the Jagiellonian University in Kraków, the oldest and leading Polish university. Grzegorz Gerwazy Gorczycki, one of the greatest Polish Baroque composers, was a lecturer at the Cheà Âmno Academy in the 1690s. Lubawa was the place where the decision was made to publish Copernicus' groundbreaking work De revolutionibus orbium coelestium.