The Kwisa ' is a river in south-western Poland

Poland

Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

, a left tributary of the Bóbr

Bóbr

Bóbr is a river which runs through the north of the Czech Republic and the southwest of Poland, a left tributary of the Oder River, with a length of and a basin area of .The Bóbr originates in the Rýchory mountains in the southeast of the Karkonosze range, where the source is...

, which itself is a left tributary of the Oder

Oder

The Oder is a river in Central Europe. It rises in the Czech Republic and flows through western Poland, later forming of the border between Poland and Germany, part of the Oder-Neisse line...

 river.

It rises in the Izera Mountains, part of the Western Sudetes

Western Sudetes

Western Sudetes are the Western part of Sudetes range system on the border of the Czech Republic, Poland and Germany. They stretch from the Bóbr river in the east to the Elbe and the Elbe Sandstone Mountains in the west....

 range, where it runs along the border with the Czech Republic

Czech Republic

The Czech Republic is a landlocked country in Central Europe. The country is bordered by Poland to the northeast, Slovakia to the east, Austria to the south, and Germany to the west and northwest....

. At the slope of the Smrk

Smrk (Jizera)

Smrk is the highest mountain in the Jizera Mountains of the Czech Republic at . "The King of the Jizera mountains" lies south of Nové Město pod Smrkem...

 massif it turns northwards, flowing along the towns of Świeradów-Zdrój

Swieradów-Zdrój

Świeradów-Zdrój is a spa town in Lubań County, Lower Silesian Voivodeship, in south-western Poland near the border with the Czech Republic. The town is located in the Kwisa valley of the Jizera Mountains, a part of the Sudetes range. It lies approximately south of Lubań, and west of the...

, Mirsk

Mirsk

Mirsk is a town in Lwówek Śląski County, Lower Silesian Voivodeship, in south-western Poland. It is the seat of the administrative district called Gmina Mirsk, close to the Czech border...

, Gryfów Śląski

Gryfów Slaski

Gryfów Śląski is a town in Lwówek Śląski County, Lower Silesian Voivodeship, in south-western Poland. It is the seat of the administrative district called Gmina Gryfów Śląski. As at 2006, the town has a population of 7,128. Prior to 1945 it was in Germany.The town is located between Zgorzelec...

, Leśna

Lesna

Leśna is a town in Lubań County, Lower Silesian Voivodeship, in south-western Poland. It is the seat of the administrative district called Gmina Leśna, close to the Czech border. Prior to 1945 it was in Germany....

, where it is dammed at the Lake Leśnia

Lake Leśnia

Lake Leśnia is a small artificial lake, located on the Kwisa river, between towns of Leśna and Gryfow Slaski in Lower Silesian Voivodeship, southwestern Poland. It was opened on July 15, 1905, after a dam had been completed near the village of Czocha...

 reservoir, to Lubań

Luban

Lubań is a town in southwest Poland north of the Jizera Mountains on the Kwisa river, with 22,137 inhabitants . Situated within the historic Upper Lusatia region, it today belongs to the Lower Silesian Voivodeship...

, Nowogrodziec

Nowogrodziec

Nowogrodziec is a town in Bolesławiec County, Lower Silesian Voivodeship, in south-western Poland. It is the seat of the administrative district called Gmina Nowogrodziec...

 and Kliczków

Kliczków

Kliczków is a village in the administrative district of Gmina Osiecznica, within Bolesławiec County, Lower Silesian Voivodeship, in south-western Poland...

. It finally joins the Bóbr river approximately 2 kilometres (1.2 mi) north-west of Małomice and 5 km (3.1 mi) south-east of Żagań

Zagan

Zagan may refer to:*Zagan - a demon in the Ars Goetia*Żagań - a town in west Poland...

. For most of its length it is in Lower Silesian Voivodeship

Lower Silesian Voivodeship

Lower Silesian Voivodeship, or Lower Silesia Province , is one of the 16 voivodeships into which Poland is currently divided. It lies in southwestern Poland...

, but it also flows through Lubusz Voivodeship

Lubusz Voivodeship

- Administrative division :Lubusz Voivodeship is divided into 14 counties : 2 city counties and 12 land counties. These are further divided into 83 gminas....

 for several kilometres before reaching its mouth.

Border river

From about 937 the southeastern outskirts of the Saxon

Duchy of Saxony

The medieval Duchy of Saxony was a late Early Middle Ages "Carolingian stem duchy" covering the greater part of Northern Germany. It covered the area of the modern German states of Bremen, Hamburg, Lower Saxony, North Rhine-Westphalia, and Saxony-Anhalt and most of Schleswig-Holstein...

 Marca Geronis

Marca Geronis

The Marca Geronis was a vast super-march in the middle of the tenth century. It was created probably for Thietmar and passed to his two sons consecutively: Siegfried and Gero...

, established in the conquered lands settled by the West Slavic Milceni

Milceni

The Milceni or Milzeni were a West Slavic tribe, who settled in the present-day Upper Lusatia region. They were first mentioned in the middle of the 9th century AD by the Bavarian Geographer, who wrote of 30 civitates which possibly had fortifications. They were gradually conquered by Germans...

 tribes, reached to the left banks of the Kwisa. After the partition of the march in 965, the lands west of the river belonged to the Imperial Margraviate of Meissen, while the adjacent territory to the east was gradually incorporated into the Silesia

Silesia

Silesia is a historical region of Central Europe located mostly in Poland, with smaller parts also in the Czech Republic, and Germany.Silesia is rich in mineral and natural resources, and includes several important industrial areas. Silesia's largest city and historical capital is Wrocław...

n region of the Early Polish state under the Piast

Piast dynasty

The Piast dynasty was the first historical ruling dynasty of Poland. It began with the semi-legendary Piast Kołodziej . The first historical ruler was Duke Mieszko I . The Piasts' royal rule in Poland ended in 1370 with the death of king Casimir the Great...

 duke Mieszko I

Mieszko I of Poland

Mieszko I , was a Duke of the Polans from about 960 until his death. A member of the Piast dynasty, he was son of Siemomysł; grandchild of Lestek; father of Bolesław I the Brave, the first crowned King of Poland; likely father of Świętosława , a Nordic Queen; and grandfather of her son, Cnut the...

 until 992. His successor Bolesław I Chrobry further extended the Polish reach of power to the west, campaigning the Milceni lands around Bautzen

Bautzen

Bautzen is a hill-top town in eastern Saxony, Germany, and administrative centre of the eponymous district. It is located on the Spree River. As of 2008, its population is 41,161...

 (Budissin), which after several years of German-Polish struggle

German-Polish War (1002–1018)

The German-Polish War which took place from 1002 to 1018 consisted of a series of struggles between the Ottonian Henry II and the Polish Piast ruler Boleslaw Chrobry. The locus of conflict was the control of Lusatia, Upper Lusatia, as well as Bohemia, Moravia and Slovakia...

 Emperor Henry II the Saint

Henry II, Holy Roman Emperor

Henry II , also referred to as Saint Henry, Obl.S.B., was the fifth and last Holy Roman Emperor of the Ottonian dynasty, from his coronation in Rome in 1014 until his death a decade later. He was crowned King of the Germans in 1002 and King of Italy in 1004...

 ceded to him according to the 1018 Peace of Bautzen

Peace of Bautzen

The Peace of Bautzen or the Peace of Budziszyn was a treaty concluded on January 30, 1018 between the Ottonian Holy Roman Emperor Henry II and the Piast ruler of Poland Boleslaw I which ended a series of Polish-German wars over the control of Lusatia and Upper Lusatia as well as Bohemia,...

.

Nevertheless the Land Budissin, later called Upper Lusatia

Upper Lusatia

Upper Lusatia is a region a biggest part of which belongs to Saxony, a small eastern part belongs to Poland, the northern part to Brandenburg. In Saxony, Upper Lusatia comprises roughly the districts of Bautzen and Görlitz , in Brandenburg the southern part of district Oberspreewald-Lausitz...

, was reconquered by Emperor Conrad II

Conrad II, Holy Roman Emperor

Conrad II was Holy Roman Emperor from 1027 until his death.The son of a mid-level nobleman in Franconia, Count Henry of Speyer and Adelaide of Alsace, he inherited the titles of count of Speyer and of Worms as an infant when Henry died at age twenty...

 in 1031 and again held by the Meissen margraves until King Henry IV of Germany

Henry IV, Holy Roman Emperor

Henry IV was King of the Romans from 1056 and Holy Roman Emperor from 1084 until his forced abdication in 1105. He was the third emperor of the Salian dynasty and one of the most powerful and important figures of the 11th century...

 in 1071 enfeoffed Duke Vratislaus II of Bohemia

Vratislaus II of Bohemia

-Literature:*Vratislav Vaníček: Vratislav II. . První český král. Vyšehrad 2004, ISBN 80-7021-655-7*Hans Patze: Die Pegauer Annalen, die Königserhebung Wratislaws v. Böhmen und die Anfänge der Stadt Pegau. JGMODtl 12, 1963, 1-62...

, his ally in the looming Saxon Rebellion

Saxon Rebellion

The Saxon Rebellion or Rebellion of the Saxons refers to the struggle between the Salian royal family and the rebel Saxons during the reign of King Henry IV. This reached its climax in the period from summer 1073 until the end of 1075, in a rebellion that involved armed conflict...

. The Bohemian rule was again confirmed by Emperor Frederick Barbarossa

Frederick I, Holy Roman Emperor

Frederick I Barbarossa was a German Holy Roman Emperor. He was elected King of Germany at Frankfurt on 4 March 1152 and crowned in Aachen on 9 March, crowned King of Italy in Pavia in 1155, and finally crowned Roman Emperor by Pope Adrian IV, on 18 June 1155, and two years later in 1157 the term...

 in favour of Duke Vladislaus II in 1158, accompanied by the royal title. Meanwhile the territory east of the Kwisa had been incorporated into the Polish Duchy of Silesia

Duchy of Silesia

The Duchy of Silesia with its capital at Wrocław was a medieval duchy located in the historic Silesian region of Poland. Soon after it was formed under the Piast dynasty in 1138, it fragmented into various Duchies of Silesia. In 1327 the remaining Duchy of Wrocław as well as most other duchies...

 in 1138, which after the Emperor's 1163 expedition to Poland was held by the Silesian Piast

Silesian Piasts

The Silesian Piasts were the oldest line of the Piast dynasty beginning with Władysław II the Exile, son of Bolesław III Wrymouth, Duke of Poland...

 descendants of Duke Władysław II the Exile. From that time on the river marked the border between the historical regions of Lower Silesia

Lower Silesia

Lower Silesia ; is the northwestern part of the historical and geographical region of Silesia; Upper Silesia is to the southeast.Throughout its history Lower Silesia has been under the control of the medieval Kingdom of Poland, the Kingdom of Bohemia and the Austrian Habsburg Monarchy from 1526...

 - i.e. the Duchy of Legnica

Duchy of Legnica

The Duchy of Legnica or Duchy of Liegnitz was one of the Duchies of Silesia. Its capital was Legnica in Lower Silesia....

 from 1248, the Duchy of Jawor

Duchy of Jawor

Duchy of Jawor was one of the Duchies of Silesia, with a capital in Jawor. It was created in 1274 as a subdivision of the Duchy of Legnica in Lower Silesia under the rule of Henry V the Fat, the eldest son of Duke Bolesław II the Bald...

 from 1274 - in the east and Upper Lusatia in the west.

Together with the lower Bóbr, the Kwisa was therefore one of the rivers considered as a possible marker of the Polish–German

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 border after World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 during the negotiations at the 1945 Potsdam Conference

Potsdam Conference

The Potsdam Conference was held at Cecilienhof, the home of Crown Prince Wilhelm Hohenzollern, in Potsdam, occupied Germany, from 16 July to 2 August 1945. Participants were the Soviet Union, the United Kingdom, and the United States...

, that finally led to the establishment of the Oder–Neisse line about 50 km (30 mi) to the west.