In the suit, lawmakers and the Supreme Court of Tatarstan, a central Russian region where ethnic Tatars outnumber ethnic Russians, challenged the constitutionality of a 2002 law that mandates the use of the Cyrillic alphabet for all official languages.

Tatarstan and some other republics with large non-Russian ethnic groups use both Russian and another tongue as official languages.In 2000, Tatarstan passed a law changing the alphabet of its Turkic language from Cyrillic to Latin. Proponents argued that the Latin alphabet is more suited than Cyrillic for transliterating the language’s sounds.

Opponents of Tatarstan’s law, including prominent Tatar figures living mostly outside the republic, as well as state officials, said it would split the community. They also pointed to difficulties in training teachers to teach the new alphabet and in printing new Tatar literature.

Tatarstan first switched to the Latin alphabet from Arabic letters in 1927. It adopted the Cyrillic alphabet in 1939 under Soviet dictator Josef Stalin, who sought to Russify all regions of the Soviet Union, no matter what their ethnic makeup.