The Rhine ( ) is one of the major rivers of Europe. The river begins in the Swiss canton of Graubünden in the southeastern Swiss Alps. It forms part of the Swiss–Liechtenstein border, then part of the Swiss–Austrian border. From Lake Constance downstream, it forms part of the Swiss–German border. After that, the Rhine defines much of the Franco-German border. It then flows in a mostly northerly direction through the German Rhineland. Finally, the Rhine turns to flow predominantly west to enter the Netherlands, eventually emptying into the North Sea.
Draining an area of 185,000 km2, it is the second-longest river in Central and Western Europe (after the Danube), at about with an average discharge of about . It also contains the most powerful waterfall in Europe, the Rhine Falls. The International Commission for the Hydrology of the Rhine Basin (CHR) and EUWID contend that the river could experience a massive decrease in volume, or even dry up completely in case of drought, within the next 30 to 80 years, as a result of the climate crisis.
The Rhine and the Danube comprised much of the Roman Empire's northern inland boundary, and the Rhine has been a vital navigable waterway bringing trade and goods deep inland since those days. The various castles and defenses built along it attest to its prominence as a waterway in the Holy Roman Empire. As of 2026, the river fleet consists of 6,900 vessels with an accumulated total weight capacity of 10 million tonnes. Among the largest and most important cities on the Rhine are Cologne, Rotterdam, Düsseldorf, Duisburg, Strasbourg, Mannheim, Ludwigshafen, Arnhem, and Basel. Its name derives from the Gaulish Rēnos. There are two German states named after the river, North Rhine-Westphalia and Rhineland-Palatinate, in addition to several districts (e.g. Rhein-Sieg). The departments of Bas-Rhin and Haut-Rhin in Alsace (France) are also named after the river. Some adjacent towns are named after it, such as Rheinau, Stein am Rhein, Rheineck, Rheinfelden (Switzerland) and Rheinfelden (Germany).
Name The variants of the name of the Rhine in modern languages (such as French , Italian , Romansh or , Dutch , Alemannic , or Ripuarian ) are all derived from the Gaulish name . This name was adapted in Roman-era geography (1st century BC) as Latin and Greek .
The spelling with Rh- in English Rhine, as well as in German and French , is due to the influence of Greek orthography and its romanization, while the vocalization -i- is due to the Proto-Germanic adoption of the Gaulish name as , via Old Frankish giving Old English ,Bosworth and Toller, An Anglo-Saxon Dictionary (1898), p. 799. Orosius (ed. J. Bosworth 1859) 1.1 Old High German , early Middle Dutch () (then also spelled or ).Rijn, Vroegmiddelnederlands Woordenboek
The modern German diphthong vowel in (also used in Romansh as or ) is a Central German development of the early modern period, with the Alemannic name keeping the older vocalism. In Alemannic, the deletion of the ending -n in pausa is a recent development; the form is largely preserved in Lucernese dialects. Schweizerisches Idiotikon s.v. Rī(n) (6,994). in Ripuarian is diphthongized, as is in Palatine. While Spanish has adopted the Germanic vocalism , Italian, Occitan, and Portuguese have retained the Latin .
The Gaulish name (Proto-Celtic or pre-Celtic ) belongs to a class of river names built from the Proto-Indo-European root "to move, flow, run", also found in other names such as the Reno in Italy.
The grammatical gender of the Celtic name (as well as of its Greek and Latin adaptation) is masculine, and the name remains masculine in German, Dutch, French, Spanish and Italian. The Old English river name was variously inflected as masculine or feminine; and its Old Icelandic adoption was inflected as feminine.Bosworth and Toller, An Anglo-Saxon Dictionary (1898), p. 799: Rín; m.; f. The Rhine [...] O. H. Ger. Rín; m.: Icel. Rín; f.
Geography
The length of the Rhine is conventionally measured in "Rhine-kilometers" (Rheinkilometer), a scale introduced in 1939 that runs from the 0 km datum at Old Rhine Bridge in the city of Konstanz, at the western end of Lake Constance, to the Hook of Holland at 1,036.20 km.
The river is significantly shortened from its natural course due to a number of canal projects completed in the 19th and 20th centuries. The "total length of the Rhine", including of Lake Constance and the Alpine Rhine is more difficult to measure objectively; it was cited as by the Dutch Rijkswaterstaat in 2010.
Its course is conventionally divided as follows: Length Section Avg. discharge Elevation Left tributaries Right tributaries 76 km The various sources and headwaters forming the Anterior and Posterior Rhine within Grisons, Switzerland 116 m3/s 584 m Aua Russein, Schmuèr Rein da Tuma, Rein da Curnera, Rein da Medel, Rein da Sumvitg (Rein da Vigliuts), Glogn (Valser Rhine), Rabiusa, Rein Posteriur/Hinterrhein (tributaries of which include the Ragn da Ferrera, Albula/Alvra, Gelgia, and Landwasser) 90 km The Alpine Rhine running through the Grisonian and St. Gall Rhine Valley (partly forming the Swiss border with Liechtenstein and Austria) 245 m3/s 400 m Tamina, Saar Plessur, Landquart, Liechtenstein inland canal, Ill, Frutz c. 60 km Lake Constance, including the short channel called Seerhein at Konstanz, connecting Obersee and Untersee 364 m3/s 395 m Alter Rhein (Rheintaler Binnenkanal), Goldach, Aach Dornbirner Ach, Bregenzer Ach, Leiblach, Argen, Schussen, Rotach, Brunnisach, Lipbach, Seefelder Aach, Stockacher Aach, Radolfzeller Aach c. 150 km The High Rhine from the exit of Lake Constance to Basel, forming a substantial part of the German-Swiss border 1,089 m3/s 246 m Thur, Töss, Glatt, Aare, Sissle. Möhlinbach, Ergolz, Birs Biber, Durach, Wutach, Alb, Murg, Wehra 362 km The Upper Rhine from Basel to Bingen forming the Upper Rhine Plain and in its upper course the Franco-German border 79 m Birsig, Ill, Moder, Lauter, Nahe Wiese, Kander, Elz, Kinzig, Rench, Acher, Murg, Alb, Pfinz, Neckar, Main 159 km The Middle Rhine between Bingen and either Bonn or Cologne is entirely within Germany, passing the Rhine Gorge; 45 m Moselle, Nette, Ahr Lahn, Wied, Sieg 177 km The Lower Rhine or downstream of Bonn, passing the Lower Rhine region of North Rhine-Westphalia 11 m Erft Wupper, Düssel, Ruhr, Emscher, Lippe c. 50 km The Nether Rhine or (shortened course of Oude Rijn within the Rhine–Meuse–Scheldt delta in the Netherlands) 2,900 m3/s 0 m Meuse Oude IJssel, Berkel
Headwaters and sources Sources
The Rhine carries its name without distinctive accessories only from the confluence of the Rein Anteriur/Vorderrhein and Rein Posteriur/Hinterrhein next to Reichenau in Tamins. Above this point is the extensive catchment area of the headwaters of the Rhine. This area belongs almost exclusively to the Swiss canton of Grisons (), ranging from Saint-Gotthard Massif in the west via one valley lying in the canton of Ticino and Sondrio (Lombardy, Italy) in the south to the Flüela Pass in the east. The Rhine is one of four major rivers taking their source in the Gotthard region, along with the Ticino (drainage basin of the Po), Rhône and Reuss (Rhine basin). The Witenwasserenstock is the triple watershed between the Rhine, Rhône and Po.
Traditionally, Lake Toma near the Oberalp Pass in the Gotthard region is seen as the source of the Anterior Rhine and the Rhine as a whole. The Posterior Rhine rises in the Rheinwald below the Rheinwaldhorn.
Anterior Rhine and Posterior Rhine
The source of the river is generally considered north of Lai da Tuma/Tomasee on Rein Anteriur/Vorderrhein, although its southern tributary Rein da Medel is actually longer before its confluence with the Anterior Rhine near Disentis.
The Anterior Rhine (, ) springs from Lai da Tuma/Tomasee, near the Oberalp Pass and passes the impressive Ruinaulta formed by the largest visible rock slide in the alps, the Flims Rockslide.
The Posterior Rhine (, ) starts from the Paradies Glacier, near the Rheinwaldhorn. One of its tributaries, the Reno di Lei, drains the Valle di Lei on politically Italian territory. After three main valleys separated by the two gorges, Roflaschlucht and Viamala, it reaches Reichenau in Tamins.
The Anterior Rhine arises from numerous source streams in the upper Surselva and flows in an easterly direction. One source is Lai da Tuma () with the Rein da Tuma, which is usually indicated as source of the Rhine, flowing through it.
Into it flow tributaries from the south, some longer, some equal in length, such as the Rein da Medel, the Rein da Maighels, and the Rein da Curnera. The Cadlimo Valley in the canton of Ticino is drained by the Reno di Medel, which crosses the geomorphologic Alpine main ridge from the south. All streams in the source area are partially, sometimes completely, captured and sent to storage reservoirs for the local hydro-electric power plants.
The culminating point of the Anterior Rhine's drainage basin is the Piz Russein of the Tödi massif of the Glarus Alps at above sea level. It starts with the creek Aua da Russein (lit.: "Water of the Russein").
In its lower course, the Anterior Rhine flows through a gorge named Ruinaulta (Flims Rockslide). The whole stretch of the Anterior Rhine to the Alpine Rhine confluence next to Reichenau in Tamins is accompanied by a long-distance hiking trail called Senda Sursilvana.
The Posterior Rhine flows first east-northeast, then north. It flows through the three valleys named Rheinwald, Schams and Domleschg-Heinzenberg. The valleys are separated by the Rofla Gorge and Viamala Gorge. Its sources are located in the Adula Alps (Rheinwaldhorn, Rheinquellhorn, and Güferhorn).
The Avers Rhine joins from the south. One of its headwaters, the Reno di Lei (stowed in the Lago di Lei), is partially located in Italy.
Near Sils the Posterior Rhine is joined by the Albula, from the east, from the Albula Pass region. The Albula draws its water mainly from the Landwasser with the Dischmabach as the largest source stream, but almost as much from the Gelgia, which comes down from the Julier Pass.
Numerous larger and smaller tributary rivers bear the name of the Rhine or equivalent in various Romansh idioms, including Rein or Ragn, including: Anterior Rhine area: Rein Anteriur/Vorderrhein, Rein da Medel, Rein da Tuma, Rein da Curnera, Rein da Maighels, Rein da Cristallina, Rein da Nalps, Rein da Plattas, Rein da Sumvitg, Rein da Vigliuts, Valser Rhine Posterior Rhine basin: Rein Posteriur/Hinterrhein, Reno di Lei, Madrischer Rhein, Avers Rhine, Jufer Rhein Albula-Landwasser area: In the Dischma valley, near Davos, far east of the Rhine, there's a place called Am Rin ("Upon Rhine"). A tributary of the Dischma is called Riner Tälli. Nearby, on the other side of the Sertig, is the Rinerhorn.
Alpine Rhine
Next to Reichenau in Tamins the Anterior Rhine and the Posterior Rhine join and form the Alpine Rhine. The river makes a distinctive turn to the north near Chur. This section is nearly 86 km long, and descends from a height of 599 meters to 396 meters. It flows through a wide glacial Alpine valley known as the Rhine Valley (). Near Sargan a natural dam, only a few meters high, prevents it from flowing into the open Sztal valley and then through Lake Walen and Lake Zurich into the Aare. The Alpine Rhine begins in the westernmost part of the Swiss canton of Graubünden, and later forms the border between Switzerland to the west and Liechtenstein and later Austria to the east.
As an effect of human work, it empties into Lake Constance on Austrian territory and not on the border that follows its old natural river bed called Alter Rhein ().