The Circassian Day of Mourning, also known as Remembrance Day for the Victims of the Caucasian War, is observed every May 21 by the Abkhazo-Adyghean peoples and commemorates the thousands of Circassians killed or displaced by the Russian Empire during the 19th century. This observance honors the memory of those affected by the Circassian genocide, which resulted in the murder and expulsion of many Circassians from their homeland to the Ottoman Empire following the Caucasian War. The day is officially recognized in the Russian autonomous republics of Adygea, Kabardino-Balkaria, and Karachay-Cherkessia, where the Circassian population is significant. Activities typically include solemn rallies, processions, and wreath-laying ceremonies. The anniversary marks the military parade held by General Pavel Grabbe on May 21, 1864, which signified the war's end, and has been observed since 1990. The remembrance is also recognized in Circassian communities worldwide, including in countries such as Turkey, Syria, Jordan, Germany, and the United States.