By Krisztina Than and Krisztina Fenyo
ESZTERGOM, Hungary/STUROVO, Slovakia (Reuters) - For Laszlo Petrik, an ethnic Hungarian living on the Slovak side of the River Danube, the treaty after World War One which led to Europe's maps being re-drawn stirs up strong feelings.
Many Hungarians view the Treaty of Trianon - signed on June 4, 1920 - as a national trauma because it took away two-thirds of the country's territory and left millions of ethnic Hungarians living in what are now Romania, Slovakia, Serbia, Austria and Ukraine.
"This is the greatest injustice ever and one that no one has remedied," Petrik said, standing in Sturovo near the bridge that connects the town with Esztergom in Hungary. The bridge, which was blown up in 1944 by German troops, was rebuilt in 2001.
"Half of my relatives are over there (in Hungary) and even though we have the European Union there is still this division."
Today, ethnic Hungarians cross the bridge to shop and work in Hungary and Hungarians like to pop over to Slovakia.
A nationwide survey conducted by the Hungarian Academy of Sciences in May showed 85% of Hungarians believe Trianon was the greatest tragedy in Hungary's history.
Prime Minister Viktor Orban, a nationalists who has been in power for a decade, in 2010 declared the June 4 anniversary a "day of national unity" as part of his efforts to restore a battered sense of national pride.
He has won popularity at home by offering ethnic Hungarians citizenship and a right to vote in elections.
Orban has never suggested re-uniting lost territories with Hungary, and relations with neighbours are mostly amiable.
However, tensions resurface, most recently with Ukraine over a language law that curbed minorities' access to education in their mother tongues.
Parliament on Thursday debated a resolution that calls on parliaments of Central European states to enshrine the right to national identity as a constitutional right.
Speaker Laszlo Kover said the struggle of ethnic Hungarians for this right was a "European affair as all European nations will face a similar struggle for identity in the coming period."
Slovak Prime Minister Igor Matovic, addressing ethnic Hungarians on Tuesday, said that even though history had redrawn the borders it was time to look ahead.
"On the 100th anniversary of the Trianon Treaty I offer my hand to act together in order to resolve our common issues," he as saying by Korkep.sk, a Hungarian-language news site in Slovakia.