After the Russo-Persian War (1804–1813) and Russo-Persian War (1826–1828), the land of the Iranian Qajar dynasty in the Caucasus were given to the Russian Empire which makes up the present territory of the Republic of Azerbaijan. Lands which Iran kept are now known as Iranian Azerbaijan. Even though they live on two sides of an international border, the Azerbaijanis are a single ethnic group. However, northerners and southerners differ due to nearly two centuries of separate social evolution of Iranian Azerbaijanis and Russian/Soviet-influenced Azerbaijan. The Azerbaijani language unifies Azerbaijanis, and is mutually intelligible with Turkmen, Qashqai, Gagauz, Turkish, and the dialects spoken by the Iraqi Turkmen, all of which belong to the Oghuz, or Western, group of Turkic languages.