Queis

Kwisa
River
Bridge at Gryfów Śląski
Country	Poland
Region	Lower Silesian Voivodeship, Lubusz Voivodeship
Source	Izerskie Garby, Jizera Mountains 50°51′8″N 15°24′9″E / 50.85222°N 15.40250°E / 50.85222; 15.40250
Mouth	Bóbr at Żelisław 51°34′33″N 15°23′39″E / 51.57583°N 15.39417°E / 51.57583; 15.39417Coordinates: 51°34′33″N 15°23′39″E / 51.57583°N 15.39417°E / 51.57583; 15.39417
Length	127 km (79 mi)
Basin	1,026 km2 (396 sq mi)
Confluence of Kwisa and Bóbr

The Kwisa [ˈkfʲisa] (German: Queis) is a river in south-western Poland, a left tributary of the Bóbr, which itself is a left tributary of the Oder river.

It rises in the Izera Mountains, part of the Western Sudetes range, where it runs along the border with the Czech Republic. At the slope of the Smrk massif it turns northwards, flowing along the towns of Świeradów-Zdrój, Mirsk, Gryfów Śląski, Leśna, where it is dammed at the Lake Leśnia reservoir, to Lubań, Nowogrodziec and Kliczków. 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. For most of its length it is in Lower Silesian Voivodeship, but it also flows through Lubusz Voivodeship for several kilometres before reaching its mouth.

From about 937 the southeastern outskirts of the Saxon Marca Geronis, established in the conquered lands settled by the West Slavic Milceni 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 Silesian region of the Early Polish state under the Piast duke Mieszko I until 992. His successor Bolesław I Chrobry further extended the Polish reach of power to the west, campaigning the Milceni lands around Bautzen (Budissin), which after several years of German-Polish struggle Emperor Henry II the Saint ceded to him according to the 1018 Peace of Bautzen.