|Donau, Dunaj, Dunărea, Donava, Duna, Дунав, Dunav, Дунáй, Dunay|
|Countries||Germany, Austria, Slovakia, Hungary, Croatia, Serbia, Bulgaria, Moldova, Ukraine, Romania|
|Cities||Ulm, Ingolstadt, Regensburg, Linz, Vienna, Bratislava, Győr, Esztergom, Budapest, Vukovar, Ilok, Novi Sad, Sremski Karlovci, Zemun, Pančevo, Belgrade|
|- location||Martinskapelle, Black Forest, Germany|
|- elevation||1,078 m (3,537 ft)|
|- length||49 km (30 mi)|
|- location||St. Georgen, Black Forest, Germany|
|- elevation||940 m (3,084 ft)|
|- length||43 km (27 mi)|
|Length||2,860 km (1,777 mi)|
|Basin||817,000 km² (315,445 sq mi)|
|Discharge||for before delta|
|- average||6,500 m3/s (229,545 cu ft/s)|
|Discharge elsewhere (average)|
|- Passau||580 m3/s (20,483 cu ft/s) |
30km before town
|- Vienna||1,900 m3/s (67,098 cu ft/s)|
|- Budapest||2,350 m3/s (82,989 cu ft/s)|
|- Belgrade||4,000 m3/s (141,259 cu ft/s)|
The Danube is the longest river in the European Union and Europe's second longest river. It originates in the Black Forest in Germany as two smaller rivers — the Brigach and the Breg rivers—which join at the eponymously named German town Donaueschingen; it is from this point that it is known as the Danube. The river flows eastwards for a distance of some 2850 km (1771 miles), passing through several Central and Eastern European capitals, before emptying into the Black Sea via the Danube Delta in Romania and Ukraine.
The Danube has been an important international waterway for centuries, as it remains today. Known to history as one of the long-standing frontiers of the Roman Empire, the river flows through — or forms a part of the borders of — ten countries: Germany, Austria, Slovakia, Hungary, Croatia, Serbia, Bulgaria, Romania, Moldova, and Ukraine; in addition, the drainage basin includes parts of nine more countries: Italy, Poland, Switzerland, Czech Republic, Slovenia, Bosnia and Herzegovina, Montenegro, Republic of Macedonia, and Albania.
The Danube basin was the site of some of the earliest human cultures. the Danubian Neolithic cultures include the Linear Pottery cultures of the mid-Danube basin. The third millennium BC Vučedol culture (from the Vučedol site near Vukovar, Croatia) is famous for its ceramics. Many sites of the sixth-to-third millemmium BC Vinča culture are sited along the Danube. The river was part of the Roman empire's Limes Germanicus.
Of importance for the Danube is also the International Commission for the Protection of the Danube River (ICPDR). The ICPDR is an international organisation consisting of 13 member states (Germany, Austria, Czech Republic, Slovakia, Slovenia, Hungary, Croatia, Bosnia and Herzegovina, Serbia, Bulgaria, Romania, Moldova, Ukraine) and the European Union. ICPDR, established in 1998, deals not only with the Danube itself, but with the whole Danube River Basin, which includes also its tributaries and the ground water resources. The goal of the ICPDR is to implement the Danube River Protection Convention, promoting and coordinating sustainable and equitable water management, including conservation, improvement and rational use of waters for the benefit of the Danube River Basin countries and their people.