KOMARNO (AFP).- The bridges across the river Danube connecting Komarom in Hungary to Komarno in Slovakia are today the epitome of a borderless Europe -- but their appearance belies the tensions that stretch back a century, and which have only recently been calmed.

As elsewhere in the region, the disintegration of the Austro-Hungarian empire at the end of World War I caused huge upheaval in what became a divided city.

For Istvan Kelemen, a 19-year-old conscript in the Austro-Hungarian army who had spent six years in prisoner-of-war camps in Siberia, returning home in 1922 was a shock.

While he was away Komarom, roughly halfway between the Slovakian and Hungarian capitals Bratislava and Budapest, had became Komarno, part of the new state of Czechoslovakia.

"He discovered that his city had moved country," his 61-year-old grandson, also called Istvan, told AFP in Komarno while leafing through wartime photos of his grandfather.

"He left for the front as a Hungarian soldier, but when he returned it was to Czechoslovakia".

Born in 1894, Kelemen lived to within six months of his 100th birthday.

Komarno was retaken by Hungary during World War II, before it rejoined Czechoslovakia until the collapse of communism in 1989.

Part of the Czech and Slovak Federative Republic between 1990 and 1992, it has been part of Slovakia since 1993.

"Before my grandfather died he used to say that he lived in six countries without ever leaving home," said Kelemen's grandson.

'Shot into the water'
Despite the turmoil it witnessed during the last century, Komarno -- whose population of around 40,000 remains roughly two-thirds ethnic-Hungarian -- still boasts handsome Habsburg-era architecture.

The green steel Elizabeth bridge was finished in 1892, while its nearby twin built in 1910, and rebuilt after detonation by Nazi German troops during World War II, is still the only railway bridge over the Danube.

When the Danube was provisionally designated as the new border after World War I, Czechoslovak forces moved in to occupy the north side of the city.

A bloody skirmish in 1919 on the bridges saw hundreds of Hungarian volunteer solders killed as they crossed the railway bridge in a bid to retake the northern side.

"Many trying to escape back across the river into Hungary were shot into the water," Emese Szamado, who runs the Komarom museum, told AFP by a monument to the victims on the Hungarian side of the Danube.

The small discreet stone was erected under communism in 1959.

Jozsef Farkas, a passing Slovak-Hungarian pensioner, pointed out that this was surprising for the time.

"Memorials of patriotic acts were rare during communism, it was mostly taboo to discuss such things," he said.

After the treaty of Trianon was signed in June 1920 the river became the official border, while bitterness in Hungary over the loss of territory lingered.

On the eve of World War II, Hungary annexed the border region north of the Danube -- including Komarno -- with the support of Hitler's Germany and Mussolini's Italy.

Grainy newsreel film shows Hungarian leader Miklos Horthy riding across Elizabeth bridge on a white horse in 1938 to celebrate the reunification.

But, with Hungary again on the losing side in World War II, the Trianon border was restored in 1947, then tightly sealed during the decades of communist rule that lasted on both sides of the Danube until 1989.

'One city, two countries'
But the collapse of communism did not immediately lead to smooth waters between the two countries.

Indeed in 2009 it was on one of the same bridges in Komarno where traffic is today so seamless that Hungarian President Laszlo Solyom held a press conference after being banned from entering Slovakia.

He had been due to unveil a monument to St Stephen, Hungary's first Christian king, in Slovakia's Komarno but had been prevented from doing so, with the Slovak government citing security concerns.

In 2010 a monument to the Trianon treaty -- also on one of Komarno's bridges -- was damaged in the run-up to Slovakian national elections.

That was typical of decades marked by moments of tension between the two countries, and during which it was frowned upon for Hungarians in Komarno to express their Magyar identity.

Nowadays however, bilingual signs proliferate and posters advertising cross-border festivals proudly boast of "one city, two countries".

"People get on with each other over there," says Emese Szamado, gesturing to the Slovakian half of the city.

"They know each other's languages, shoppers come over here to shop in Tesco, while we go over there to visit Kaufland," said Emese Szamado.

Near the old railway bridge, a new road bridge is under construction across the Danube to link highways in Slovakia and Hungary from next year.


© Agence France-Presse