 He discovered and studied several old Georgian manuscripts, made substantial research into the history of the Georgian Orthodox Church and published the pieces of medieval and early modern Georgian literature.Beyond that, Iosseliani was the first scholar to have embarked on the study of evolution of the urban settlements in Georgia.One of his last major works, that on the reign of the last king of Georgia, George XII (1798-1800), was published posthumously in the Georgian magazine "Iveria" in 1880.