neisse

Neisse (German: Neisse; Polish: Nysa; Czech: Nisa) is a name applied to several rivers and places in Central Europe, primarily in Poland, Germany and the Czech Republic. It is most commonly associated with three rivers and with the historic town of Nysa.

The Lusatian Neisse (Nysa Łużycka / Lužická Nisa) rises in the Czech Republic and flows northward, forming much of the modern border between Poland and Germany before joining the Oder. It is the better-known “Neisse” in international context because the Oder–Neisse line—established after World War II—uses this river as part of the boundary between the two countries. Two other Polish rivers with the name include the Nysa Kłodzka (Eastern Neisse), a tributary of the Oder in southwestern Poland, and the Nysa Łączna (sometimes called the Western Neisse), among smaller rivers that bear the same root name.

The town of Nysa in southwestern Poland was historically known by its German name Neisse and has a long Central European history as a regional ecclesiastical and trading center. The name “Neisse/Nysa/Nisa” likely derives from old Indo-European roots for flowing water and appears across Slavic and Germanic toponymy in the region.

Because the name refers to multiple geographical features, context—such as a national or historical reference—is typically needed to identify which Neisse is intended.