Yemelyan Pugachev
Yemelyan Ivanovich Pugachev () (c. 1742 – ) was a Russian Cossack who led a great popular insurrection during the reign of Catherine the Great, claiming to be her late husband, Emperor Peter III. Alexander Pushkin wrote a notable history of the rebellion, "The History of Pugachev", and he recounted some of the events in his novel "The Captain's Daughter" (1836).
Tarkhan Gaziyev
Later, in September 2010, Gaziyev appeared on video alongside fellow field commanders Khuseyn Gakayev and Aslambek Vadalov; in the clip, they denounced Umarov and declared Gakayev the leader of the re-organized Chechen resistance. The genesis of the dispute was over the precise vision of an independent state in the North Caucasus as well as Umarov's allegedly autocratic leadership style; in siding with Gakayev and Vadalov, as well as the Saudi-born Muhannad (whom Umarov would accuse of fomenting dissent within the insurgency ranks in tandem with Gaziyev), Gaziyev had "opted for moderate radicals with views closer to traditional Chechen nationalists." The fact that Gaziyev had sided with the Chechen nationalists was considered a huge blow to Umarov's power and credibility; numerous middle- and lower-ranking militant leaders departed with the four veteran field commanders, putting Umarov in an increasingly isolated position. In response, Umarov stripped Gakayev, Vadalov, Gaziyev, and Muhannad of their titles and appointments.