THOUSANDS of flood victims across the Balkans who were moved out of their homes as the Danube continued to burst its banks yesterday can take meagre comfort from their bit parts in the latest episode of the river’s dramatic history.

Muse to writers and composers, host to imprisoned kings and Sufi mystics, the Danube has shaped Europe’s culture, history and geography for millennia, especially in the central and eastern parts of the continent.

The great castles and fortresses that line its banks from Austria to the Balkans are a reminder of man’s attempts to tame the river. But the devastating floods show that while empires rise and fall, the Danube remains eternal.

Since man first settled on its banks the river has formed a natural frontier. The Romans found its fast-flowing waters an effective frontier against the barbarian hordes during the 1st century AD.

Each of the cities and countries through which it flows has been shaped by the river, and its 1,770 miles (2,850 kilometres) link a diverse continent by more than geography.

The Danube is the continent’s largest river after the Volga. It begins in the Black Forest in Germany and flows through, or touches, ten countries before spilling into the Black Sea. There are rumours of buried emperors’ palaces – and hints of treasure – in the islands that dot the river around Budapest, the Hungarian capital.

In his magisterial work Danube, the Italian writer Claudio Magris records the legend of Jason and the Argonauts sailing down the river, heading for Colchis, now in western Georgia, across the Black Sea, bearing the Golden Fleece. The Danube also marked the border between the AustroHungarian and Ottoman empires: Belgrade, the capital of Serbia, was for centuries an important Ottoman city, the northernmost point of “ Turkey-in- Europe”, while the village of Zemun, on the other side of the river, marked the start of Habsburg territory. Today the two settlements are united in one city.

The river has traditionally marked the route east, onwards to the Mediterranean and the Holy Land. The Crusader king Richard the Lionheart was captured at the end of the 12th century and imprisoned by the Duke of Austria at Schloss Durnstein, above the river.

Its power has also inspired writers and composers. Johann Strauss wrote The Blue Danube while travelling down the river, although its waters are usually grey or brown. The music became the defining tune of the Austro-Hungarian Empire. Vienna has an ambiguous relationship with the river. Unlike neighbouring capitals, the Danube does not flow proudly through the centre. The paradox of Vienna is that a city that considers itself the most western of capitals is Europe’s gateway to the east, through the Danube most of all.

Bratislava, capital of Slovakia, has no such doubts. The New Bridge, which spans the river, dominates the city centre skyline. Much of old Bratislava was demolished to make way for the 1960s monument to Soviet-era gigantism. But, while communist architecture remains, Slovakia is changing rapidly. To the chagrin and disbelief of the neighbouring Viennese, who long looked down on Slovaks as country cousins, Bratislava is booming.

A tram once linked Vienna to central Bratislava, or Pressburg as it was known during the Austro-Hungarian empire. Now transport is again revitalising the city. Budget airlines make its airport a cheap alternative to Vienna and the once-dilapidated communist-era port is becoming a regional transport hub.

The Danube has also been a grave.

In Budapest a small, poignant sculpture stands by five-star hotels alongside the Corso, the riverbank pedestrian zone. A row of shoes, cast in metal, commemorates the Jews who were taken there at gunpoint in the winter of 1944, ordered to stand facing the waters tied together, before being gunned down into its depths by the Hungarian Arrow Cross Nazis.

In comparison to Leningrad and Stalingrad, historians have paid little attention to the siege of Budapest that lasted from late 1944 to February 1945. By early 1945 the river marked the border between liberation and subjugation, as the Soviet army pounded the last redoubt of the SS in Buda castle from the city’s Pest side, before the SS finally surrendered.

Less than 50 years later, the Danube once again echoed to the sounds of war.

The Danube forms part of the border between Croatia and Serbia and control of the waters was a strategic imperative. The pretty baroque Croatian town of Vukovar was once an important trading post on the river. But it became a byword for destruction as Serb gunners pounded it throughout the autumn of 1991 before the city fell in November. A cosmopolitan riverside society of Croats and Serbs, Hungarians and Germans has now vanished in the rubble.

The Turkish island of Ada Kaleh — Island Fortress — has also vanished under the waters during the construction of a hydroelectric power station by the Iron Gates gorge that separates Serbia and Romania. The island was conquered and reconquered by the Turks and Austrians. It was home to Sufi mystics and smugglers.

History and geography have ensured that the Balkan nations of Serbia, Romania and Bulgaria have been worst hit by the floods. It has left them with the legacy of communism: weak central governments, poor infrastructure and under-funded national agencies that have been overwhelmed by the devastation.

Geography, too, has played an important role: in its upper reaches in Germany, Austria, Slovakia and Hungary, the Danube is manageable, even at flood-tide.

But now, in Serbia, Romania and Bulgaria, the river is miles wide and seems beyond the power of man to control.

The Blue Danube is now a threat to the homes and livelihoods of many.

.