The “gay propaganda law,” as it became known, is actually a series of statutes introduced at regional levels in 2003 and 2006 and at the federal level in 2013, essentially proscribing public mention of homosexuality.

In particular, the 2013 law banned “the promoting of nontraditional sexual relationships among minors” and “creating a distorted image of the social equivalence of traditional and nontraditional sexual relationships.”

Critics said the law’s very wording promoted insidious stereotypes that gay people promote a “homosexual lifestyle,” or even worse, prey on children.

The three activists who sued — Nikolai V. Bayev, 42; Aleksei A. Kiselev, 33; and Nikolai A. Alekseyev, 39 — staged demonstrations from 2009 to 2012 in the cities of Ryazan, Arkhangelsk and St. Petersburg, carrying banners stating that homosexuality is natural, not a perversion. They were arrested and fined.

They challenged the verdicts before Russia’s Constitutional Court, which upheld the ban on the grounds of protecting morals. The three men then brought their complaints to the European Court of Human Rights in Strasbourg, France.

The judges ruled 6 to 1 against Russia. The judge who dissented, Dmitry Dedov, is Russian.

Mr. Alekseyev praised the ruling as “a destructive blow against one of the pillars of Russia’s modern ideology,” and “another confirmation that representatives of L.G.B.T. community are under discrimination in Russia and their rights are violated.” Read more via New York Times