Dmitry Yelizarov, 31, was arrested in April 2007 for his involvement in a fight a year earlier outside a Moscow court building, but was convicted only in March 2008 and sentenced to 18 months' imprisonment.
The fight broke out on April 12, 2006 when Yelizarov was on his way to a court hearing on the Russian authorities' refusal to register the National Bolshevik Party.
The party has twice been outlawed, in June 2005 and in April 2007, and has been barred from election registration.
Yelizarov filed a lawsuit complaining about the excessive length of his detention pending trial, and the Strasbourg court ruled that his one-year detention violated the European Convention on Human Rights.
This is the third appeal to the Strasbourg court by National Bolshevik Party members involved in the 2006 incident. Earlier, activists Roman Popkov and Alexei Makarov won 5,000 euros each for their 2.5-year detentions.
Russia has lost the majority of cases brought against it in the Strasbourg court. In 2008, the court ruled against Russia 245 times. Overall, around 20% of all appeals made to the court in the past decade have involved Russia.
The National Bolsheviks, founded by radical writer Eduard Limonov, has pursued 'direct action' tactics by publicly attacking people they consider to be symbols or allies of the Kremlin.
Group members are known to have thrown mayonnaise and tomatoes at prominent public figures, including ex-Prime Minister Mikhail Kasyanov, former NATO Secretary Lord George Robertson, and Russian film director Nikita Mikhalkov. Activists have also staged protests by breaking into government offices in Moscow.