Azerbaijan (Iran)
After being defeated by Russian Empire, Qajar Persia gave all of its territories in the North Caucasus and Transcaucasia to Russia via the Treaty of Gulistan of 1813 and the Treaty of Turkmenchay of 1828. The territories south of the Aras River, which comprised the region historically known as Azerbaijan, became the new north-west frontier of the Persian Empire and later Iran. The territories north of the Aras River, which were not known by the name Azerbaijan at the time of their capture by Russia, were absorbed into the Russian Empire. It was later incorporated into the Soviet Union as the Azerbaijan Soviet Socialist Republic, and finally became the independent Republic of Azerbaijan when the Soviet Union dissolved.