The paper is an attempt at writing of the new conceptual biography of a renowned Muslim reformist leader in late tsarist and early Soviet Caucasus. After 'Ali al-Ghumuqi more known under the name of Kayaev (1878-1943) from the Dagestani village of Ghumuq fell the victim of the Stalinist political repressions and then was gradually rehabilitated, historians often presented him a leftist journalist and politician close to the Bolsheviks, sometimes also a bibliophile who collected one of the largest private libraries of Muslim Oriental manuscripts and documents. Seriously revising this not very correct image the authors of this article investigate rather his academic research activities that allow rethinking Kayaev as a Muslim historian revisionist. The focus is made on his Oriental source studies that traced the future development of the famous Dagestani school of academic Oriental studies in the twentieth century, as well as on Kay - aev's original treatment of Muslim historiography he considered through the lenses of Muslim peoples' development as principal historical actors.