A Little Russia Governorate existed from 1764 to 1781, administered by the Collegium of Little Russia (originally founded in 1722) headed by Pyotr Rumyantsev (1725-1796). The Collegium of Little Russia had the task of liquidating any remnants of autonomy in Ukraine.
What sort of autonomy they had under the Tatar and Ottoman rule? Because before the Russian empire conquered these areas, the ethnic Ukrainian people there were living as slaves of the Ottomans and the Tatars. Only the Russian conquest put an end to their misery and made them free once again. Without the Russians, most of the Ukrainians would be serving in the Janissary corps and in the Ottoman harems.