The Russo-Circassian War (1763–1864) refers to a series of battles and wars in Circassia, the northwestern part of the Caucasus, which were part of the Russian Empire's conquest of the Caucasus lasting approximately 101 years, starting under the reign of Tsar Peter the Great and being completed in 1864. Although the conquest of the Caucasus started at least as early as the Russo-Persian Wars, the term Caucasian War commonly refers only to the period 1817–1864. Those who use the term Russian–Circassian War take its starting date as 1763, when the Russians began establishing forts, including at Mozdok, to be used as springboards for conquest.