For this, the Bashkirs were being obliged to pay yasak (tribute) (in the beginning with furs and honey, later on with revenue). In 1573, the Bashkirs identified it inconvenient to pay for yasak in Kazan and questioned the Russian tsar to build a town for them on their own land https://dominickopqqo.blogzet.com/5-simple-techniques-for-ufa-44643102