Which countries does the Danube River flow through?

The mapped course of the Danube River runs through or along Germany, Austria, Slovakia, Hungary, Croatia, Serbia, Romania, Bulgaria and Ukraine.

Where does the Danube River begin and end?

Source: Black Forest (Schwarzwald, Germany). Mouth: Black Sea (Danube Delta, Romania/Ukraine).

How long is the Danube River?

About 2,850 km (1,771 miles), draining a basin of about 801,463 km².

Which civilizations grew up along the Danube River?

Among them: Celtic Tribes, Roman Empire (Danubian Limes), Byzantine Empire, Ottoman Empire and Austro-Hungarian Empire.

2,850 km Total LengthDrainage Basin: 801,463 km²

The Danube River (Danuvius)

Ancient Appellations: Danuvius (Roman / Latin) • Istros (Ancient Greek) • Donau (German) • Duna (Hungarian)

Europe’s second-longest river and its ultimate historical frontier, serving for centuries as the fortified northern border (Limes) of the Roman Empire.

Hydrological Influence & Ancient Statecraft

Flowing eastward across ten contemporary European nations, the Danube linked Central Europe with the Balkans and the Black Sea. For the Roman Empire, the river was not merely a border but a strategic highway patrolled by the Classis Pannonica fleet. Trajan built his famous stone bridge across the Danube in 105 CE to conquer Dacia, and for centuries thereafter it remained the battleground between Roman legions, Germanic tribes, and steppe nomadic incursions.

Agricultural Surplus & Flood Pulse Ecology

Encompassed the fertile Hungarian Plain (Pannonian Basin) and Wallachian plain, producing grain, wine, and livestock for imperial centers.

Hydrological Anatomy

✓The Iron Gates gorge between Serbia and Romania, a dramatic limestone canyon break
✓Second largest river delta in Europe, a pristine wetland biosphere reserve
✓Interlinks four historic capital cities: Vienna, Bratislava, Budapest, and Belgrade
✓Strategic navigable water corridor linking Western Europe directly with the Black Sea

About the Danube

The Danube ( DAN-yoob; see also other names) is a river in Europe, the second-longest after the Volga. It flows through Central and Southeastern Europe, from the Black Forest of Germany south through the Danube Delta in Romania into the Black Sea. A large and historically important river, it was once a frontier of the Roman Empire. In the 21st century, it connects ten European countries, running through their territories or marking a border. Originating in Germany, the Danube flows southeast for 2,850 km (1,770 mi), passing through or bordering Austria, Slovakia, Hungary, Croatia, Serbia, Romania, Bulgaria, Moldova, and Ukraine. Among the many cities on the river are four national capitals: Vienna, Bratislava, Budapest, and Belgrade. Its drainage basin amounts to 817,000 km2 (315,000 sq mi) and extends into nine more countries.

The Danube's longest headstream, the Breg, rises in Furtwangen im Schwarzwald, while the river carries its name from its source confluence in the palace park in Donaueschingen onwards. Since ancient times, the Danube has been a traditional trade route in Europe. Today, 2,415 km (1,501 mi) of its total length are navigable.

Encyclopedic summary adapted from Wikipedia: Danube (CC BY-SA 4.0).

Danube in Depth

Geography

Classified as an international waterway, it originates in the town of Donaueschingen, in the Black Forest of Germany, at the confluence of the rivers Brigach and Breg. The Danube then flows southeast for about 2,730 km (1,700 mi), passing through four capital cities (Vienna, Bratislava, Budapest, and Belgrade) before emptying into the Black Sea via the Danube Delta in Romania and Ukraine.

Once a long-standing frontier of the Roman Empire, the river passes through or touches the borders of 10 countries. Its drainage basin extends into nine more (ten if Kosovo is included).

Middle Basin, usually called the Pannonian Basin or Carpathian Basin, between the Devín Gate and the Iron Gates. It includes the Hungarian plains Kisalföld and Alföld.

History

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. Many sites of the sixth-to-third millennium BCE Vinča culture (Vinča, Serbia), are sited along the Danube. The third millennium BCE Vučedol culture (from the Vučedol site near Vukovar, Croatia) is famous for its ceramics.

Darius the Great, king of Persia, crossed the river in the late 6th century BCE to invade European Scythia and to subdue the Scythians.

Alexander the Great defeated the Triballian king Syrmus and the northern barbarian Thracian and Illyrian tribes by advancing from Macedonia as far as the Danube in 336 BCE.

Geology

Although the headwaters of the Danube are relatively small today, geologically, the Danube is much older than the Rhine, with which its catchment area competes in today's southern Germany. This has a few interesting geological complications. Since the Rhine flows north towards the North Sea, a continental divide beginning at Piz Lunghin divides large parts of southern Germany, which is sometimes referred to as the European Watershed.

Before the last ice age in the Pleistocene, the Rhine started at the southwestern tip of the Black Forest, while the waters from the Alps that today feed the Rhine were carried east by the so-called Urdonau (original Danube).

Sections adapted from Wikipedia: Danube (CC BY-SA 4.0).

Danube: Key Facts

Key facts about Danube
Average discharge	5,433 m³/s
Drainage system	Danube basin
Tributaries	Inn, Sava, Tisza, Drava, Isar, Lech, Riss, Westernach

Facts from Wikidata Q1653 (CC0).

Iron Gate I Dam

Concrete Gravity dam · Romania / Serbia

Iron Gate I Dam is a concrete gravity dam on the Danube in Romania / Serbia, standing 60 m (197 ft) high and completed in 1972. It carries an installed hydroelectric capacity of 2,192 MW. The structure impounds Iron Gate Reservoir.

The Iron Gate I Hydroelectric Power Station (Romanian: Porțile de Fier I, Serbian: Ђердап I/Đerdap I) is the largest dam on the Danube river and one of the largest hydro power plants in Europe. It is located on the Iron Gate gorge, between Romania and Serbia.

The Romanian side of the power station produces approximately 5.24 TWh annually, while the Serbian side of the power station produces 5.65 TWh.

Adapted from Wikipedia: Iron Gate I Hydroelectric Power Station (CC BY-SA 4.0).

Dam type: Concrete Gravity
Structural height: 60 m (197 ft)
Installed capacity: 2,192 MW
Impounded river: Danube
Reservoir: Iron Gate Reservoir
Location: Romania / Serbia
Year completed: 1972
Height rank: #71 of 115 indexed
Output rank: #29 of 102 indexed
Coordinates: 44.6708°, 22.5292°

Notable: Largest dam on the Danube and one of Europe's largest hydro facilities, taming the historic Danube cataracts.

Among the 115 dams indexed in YearMaps, Iron Gate I Dam ranks #71 by structural height, behind Jinping-I Dam (305 m). By installed generating capacity it ranks #29, behind Three Gorges Dam (22,500 MW).

Nearest cities: Drobeta-Turnu Severin (11 km), Târgu Jiu (72 km), Reșița (86 km).

View on the live map

More about Iron Gate I Dam

History

The project started in 1964 as a joint-venture between the governments of Romania and Yugoslavia for the construction of a major dam on the Danube River which would serve both countries. At the time of completion in 1972, it was the 10th largest hydroelectric power stations in the world with twelve Kaplan turbines generating 2,052 MW, divided equally between the two countries at 1,026 MW each.

The small inhabited island of Ada Kaleh was submerged during the construction.

As the original turbines' 30 years lifespan came to an end, in 1998 the Romanian half of the dam started a program of modernization. As part of this program, the first of the turbines was stopped in 1999. By 2007 the program was completed and the Romanian half of the dam's operations were back to full capacity.

Sections adapted from Wikipedia: Iron Gate I Hydroelectric Power Station (CC BY-SA 4.0).

Danube River: Quick Answers

Which countries does the Danube River flow through?: The mapped course of the Danube River runs through or along Germany, Austria, Slovakia, Hungary, Croatia, Serbia, Romania, Bulgaria and Ukraine.
Where does the Danube River begin and end?: Source: Black Forest (Schwarzwald, Germany). Mouth: Black Sea (Danube Delta, Romania/Ukraine).
How long is the Danube River?: About 2,850 km (1,771 miles), draining a basin of about 801,463 km².
Which civilizations grew up along the Danube River?: Among them: Celtic Tribes, Roman Empire (Danubian Limes), Byzantine Empire, Ottoman Empire and Austro-Hungarian Empire.