The Eider ( ; ;

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

: ''Egdor'' or ''Eidora'') is the longest river in the

German German(s) may refer to: * Germany, the country of the Germans and German things **Germania (Roman era) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizenship in Germany, see also Ge ...

state State most commonly refers to: * State (polity), a centralized political organization that regulates law and society within a territory **Sovereign state, a sovereign polity in international law, commonly referred to as a country **Nation state, a ...

Schleswig-Holstein Schleswig-Holstein (; ; ; ; ; occasionally in English ''Sleswick-Holsatia'') is the Northern Germany, northernmost of the 16 states of Germany, comprising most of the historical Duchy of Holstein and the southern part of the former Duchy of S ...

. The river starts near Bordesholm and reaches the southwestern outskirts of

Kiel Kiel ( ; ) is the capital and most populous city in the northern Germany, German state of Schleswig-Holstein. With a population of around 250,000, it is Germany's largest city on the Baltic Sea. It is located on the Kieler Förde inlet of the Ba ...

on the shores of the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by the countries of Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden, and the North European Plain, North and Central European Plain regions. It is the ...

, but flows to the west, ending in the

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

. The lower part of the Eider was used as part of the

Eider Canal The Eider Canal (also called the Schleswig-Holstein Canal) was an artificial waterway in southern Denmark (later northern Germany) which connected the North Sea with the Baltic Sea by way of the rivers Eider and Levensau. Constructed between ...

until that canal was replaced by the modern

Kiel Canal The Kiel Canal (, until 1948 called in German the ) is a fresh water canal that links the North Sea () to the Baltic Sea (). It runs through the Germany, German states of Germany, state of Schleswig-Holstein, from Brunsbüttel to the Holtenau di ...

. In the

Early Middle Ages The Early Middle Ages (or early medieval period), sometimes controversially referred to as the Dark Ages (historiography), Dark Ages, is typically regarded by historians as lasting from the late 5th to the 10th century. They marked the start o ...

the river is believed to have been the border between the related Germanic tribes, the

Jutes The Jutes ( ) were one of the Germanic people, Germanic tribes who settled in Great Britain after the end of Roman rule in Britain, departure of the Roman Britain, Romans. According to Bede, they were one of the three most powerful Germanic na ...

and the Angles, who along with the neighboring

Saxons The Saxons, sometimes called the Old Saxons or Continental Saxons, were a Germanic people of early medieval "Old" Saxony () which became a Carolingian " stem duchy" in 804, in what is now northern Germany. Many of their neighbours were, like th ...

crossed the North Sea from this region during this period and settled in England. During the

High Middle Ages The High Middle Ages, or High Medieval Period, was the periodization, period of European history between and ; it was preceded by the Early Middle Ages and followed by the Late Middle Ages, which ended according to historiographical convention ...

the Eider was the border between the

and the

Danes Danes (, ), or Danish people, are an ethnic group and nationality native to Denmark and a modern nation identified with the country of Denmark. This connection may be ancestral, legal, historical, or cultural. History Early history Denmark ...

, as reported by

Adam of Bremen Adam of Bremen (; ; before 1050 – 12 October 1081/1085) was a German medieval chronicler. He lived and worked in the second half of the eleventh century. Adam is most famous for his chronicle '' Gesta Hammaburgensis ecclesiae pontificum'' ('' ...

in 1076. For centuries it divided

Denmark Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...

and the

Holy Roman Empire The Holy Roman Empire, also known as the Holy Roman Empire of the German Nation after 1512, was a polity in Central and Western Europe, usually headed by the Holy Roman Emperor. It developed in the Early Middle Ages, and lasted for a millennium ...

. Today it is the border between

Schleswig The Duchy of Schleswig (; ; ; ; ; ) was a duchy in Southern Jutland () covering the area between about 60 km (35 miles) north and 70 km (45 mi) south of the current border between Germany and Denmark. The territory has been di ...

Holstein Holstein (; ; ; ; ) is the region between the rivers Elbe and Eider (river), Eider. It is the southern half of Schleswig-Holstein, the northernmost States of Germany, state of Germany. Holstein once existed as the German County of Holstein (; 8 ...

and Eiderland, the northern and southern parts, respectively, of the modern German state of Schleswig-Holstein. The Eider flows through the following towns: Bordesholm, Kiel,

Rendsburg Rendsburg (, also ''Rensborg'', , also ''Rensborg'') is a town on the Eider (river), River Eider and the Kiel Canal in the central part of Schleswig-Holstein, Germany. It is the capital of the ''Kreis'' (district) of Rendsburg-Eckernfoerde, Rends ...

, Friedrichstadt and Tönning. Near Tönning it flows into the North Sea. The

estuary An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime enviro ...

has

tidal flats Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal ...

and

brackish water Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuary ...

. The mouth of the river is crossed by a closeable storm surge barrier, the Eider Barrage. Eider Treene2

Navigation

A tidal

lock Lock(s) or Locked may refer to: Common meanings *Lock and key, a mechanical device used to secure items of importance *Lock (water navigation), a device for boats to transit between different levels of water, as in a canal Arts and entertainme ...

provides access for boats through the Eider Barrage. The fishing port of Tönning lies upstream of the barrier, while Friedrichstadt is further upstream. At Friedrichstadt a lock gives access to the River Treene. The Eider remains tidal as far as the lock at Nordfeld, above Friedrichstadt. There is a further lock named near Wrohm, upstream of Nordfeld. A further beyond Lexfähre is the junction with the short Gieselau Canal, which provides a navigable link to the

at Oldenbüttel. The Eider therefore provides an alternative route from the

to the Kiel Canal, avoiding the tides of the estuary of the

Elbe The Elbe ( ; ; or ''Elv''; Upper Sorbian, Upper and , ) is one of the major rivers of Central Europe. It rises in the Giant Mountains of the northern Czech Republic before traversing much of Bohemia (western half of the Czech Republic), then Ge ...

. The head of navigation lies a further upstream at

. Although it is adjacent to the Kiel Canal, through passage is no longer possible. Storm tide barrage at the Eider river - photo

References

{{Authority control Rivers of Schleswig-Holstein Holstein Federal waterways in Germany Kiel Canal Rivers of Germany

Navigation

See also

References