Warmia (Latin: Varmia, German: Ermland) is a region between Pomerania and Masuria in northeastern Poland. Together with Masuria it forms the Warminsko-Mazurskie Voivodship. To the west of Warmia is Pomesania, to the south Chełmno Land, Sassinia and Galindia (later called Masuria) and to the east Sambia. In the north it borders the Vistula Bay. Because it is located in a border area, Warmia has been under the rule of various rulers over its history; the most notable include the Teutonic Order, Poland, and the Kingdom of Prussia.
The area is associated with the Old Prussian tribe of Warmians (a.k.a. Warms, Varms, Varmi, Warmians, Varmians, Latvian: Vārmieši) exterminated by the Teutonic Knights.
In the early Middle Ages the area was inhabited by various Old Prussian tribes, such as the Pomesanians, Pogesanians, Warmians, Natangians, Bartians, Sambians, Nadrovians, Scalovians, Galindians and Sassinians. However, these tribes only began to coordinate after the 12th century when they were subject to crusade from Teutonic Order.
As the Polish state grew in power, Poles tried to Christianize the Prussians, but this led to conflict and skirmishes, including the martyring of Adalbert of Prague.
Because of his inability to subdue the Prussians, in 1226 Konrad I of Masovia invited the Teutonic Knights to Christianise the pagan Prussians. They were given the small Chełmno Land as a fief for the duration of their crusade, but quickly acquired more land to the north and east. Their actions were considered violations of signed treaties, and the knights were also accused of forging land grants. By the end of the 13th century most of the Prussian region, including Warmia, was conquered by the Teutonic Order. The native Prussians were either killed off or reduced to Serfdom. The Order received the reins of government from Emperor Frederick II in 1228. The grant was confirmed by a Papal bull from Pope Gregory IX in 1234, although Poland never recognized the rights of the Order to rule the country.
The Bishopric of Warmia was one of four dioceses created in 1242 by the Papal legate William of Modena. Between the 13th and 17th centuries Warmia as well as other parts of Prussia were colonised by Germans in the north and Poles in the south. The bishopric was part of a Polish province of the church. The Bishops of Warmia were usually Germans or Poles, although Enea Silvio Piccolomini, the later Pope Pius II, was an Italian bishop of the diocese.
The Second Treaty of Toruń in 1466 removed Warmia from the control of the Teutonic Knights and placed it under the sovereignty of the King of Poland as part of the province of Royal Prussia. This was confirmed in the Treaty of Piotrków Trybunalski (December 7, 1512), which conceded to the King of Poland a limited influence in the election of bishops. After the Union of Lublin in 1569 Warmia was directly included into the Polish crown within the Polish-Lithuanian Commonwealth.
During the Partitions of Poland Warmia was incorporated into the Kingdom of Prussia in 1772, while the property of the bishop was confiscated by the Prussian state. Ignacy Krasicki, the last Prince-Bishop as well as a Polish writer, was nominated to the Archbishopric of Gniezno. The Prussian census in 1772 showed a total population of 96,547 including an urban population of 24,612 in 12 towns. 17,749 houses were listed and the biggest city was Braniewo.
From 1772-1945 Warmia shared its history with Lutheran East Prussia, with the exception that the people of Warmia remained Catholic. The population of northern Warmia spoke standard German (as opposed to Low German used in the rest of East Prussia), while the south was populated by Polish-speaking Warmiaks. In 1873 the Polish language was forbidden in all schools in Warmia, including Polish schools founded in the 16th century. In 1900 Warmia's population was 240,000.
After World War I, Poles were subject to persecution by the German government during the Weimar Republic. Polish children speaking their language were punished in schools and often had to wear signs with insulting name, such as "Pollack".
During the Nazi period, Poles in Warmia were subject to even harsher persecution by German authorities, and, with the outbreak of World War II, many prominent Polish cultural activists were murdered, such as Seweryn Pieniężny and Leon Włodarczak. Peasants who showed interest in Polish culture were frequently murdered as well.
In 1945 Warmia was de facto included within the borders of post-war Poland, as a result of the decisions of the Potsdam Conference; ethnic Germans were expelled from East Prussia to Germany. The governments of the two German states accepted Germany's post-war eastern border by treaties in 1950 and 1970 and finally de jure in the prelude to the 1990 reunification. Today Warmia is part of the administrative region Warmia-Masuria.