May 21 is Circassian Memorial Day, when the worldwide Circassian community remembers the Russian-led Circassian Genocide of the 1860s, part of Russia’s attempt to expand into the Caucasus. Circassians (also known as the Adyghe) are largely Sunni Muslim, but their language is Northwest Caucasian, i.e. not Indo-European. Sochi, the site of the 2014 Winter Olympics, was once the Circassian capital.
I have discovered that the Circassians fly a distinctive flag, which dates from the nineteenth century and was adopted as the flag of the Russian Republic of Adygea 1992. Apparently it was designed by David Urquhart, a Scottish diplomat serving in the Ottoman Empire. The stars reference the twelve Adyghe princedoms.