Circassia is usually referred to the union of Adyghe and Abaza people between 18-19th centuries, which was formed as result of Russian agressive expansionism. Though the term is coind for Adyghe people these days, historically it was used as a reference to all ethnic groups of the North-West Caucasus like Abaza people, Ossetians, Taulu people (Karachay-Malkar), and even to Ingushs and Chechens.
Legally and internationally, the Treaty of Belgrade of 1739 between Austria and Turkey provided for the recognition of the independence of Eastern Circassia (Kabarda). Both the Russian Empire and the Ottoman Empire recognized it, and the great powers at the time witnessed the treaty. The Congress of Vienna held in the period between 1814-1815 also stipulated the recognition of the independence of Circassia. In 1837, Adyghe and Abaza leaders sent letters to European countries requesting legal recognition. Following this, the United Kingdom recognized Circassia. However, during the Russian-Circassian War, the Russian Empire did not recognize Circassia as an independent region, and treated it as Russian land under rebel occupation, despite having no control or ownership over the region. Russian generals referred to the Circassians not by their ethnic name, but as "mountaineers", "bandits", and "mountain scum".
Although Circassia is the original homeland of the Ayghe and Abaza people, today most of them live in exile, following the Circassian genocide.