Restrictions in occupation, heavy taxation, and discrimination against non-Christians blocked the cultural and economic development of the Tatars. Several rebellions and peasants' wars broke out as a result. During the Time of Troubles, the Kazan khanate regained its independence with the aid of factions within the Russian army. Cangali bek, a Tatar nobleman, led another revolution in 1616. Other insurrections among the Volga Tatars included the Bolotnikov movement (1606–1607), Batırşa movement (1755–1756), and Pugachev's war (1773–1775). Other peoples of the Idel-Ural region took part in these conflicts.