Samara, known from 1935 to 1991 as Kuybyshev, is the largest city and administrative centre of Samara Oblast in Russia. The city is located at the confluence of the Volga and the Samara rivers, with a population of over 1.14 million residents, up to 1.22 million residents in the urban agglomeration, not including Novokuybyshevsk, which is not conurbated. The city covers an area of 541.382 square kilometers (209.029 sq mi), and is the eighth-largest city in Russia and tenth agglomeration, the third-most populous city on the Volga, as well as the Volga Federal District.

Kazan is the largest city and capital of Tatarstan, Russia. The city lies at the confluence of the Volga and the Kazanka Rivers, covering an area of 425.3 square kilometres, with a population of over 1.3 million residents, and up to nearly 2 million residents in the greater metropolitan area. Kazan is the fifth-largest city in Russia, being the most populous city on the Volga, as well as within the Volga Federal District.