Our digital age has produced resources and methods which call for a significant change in how historians work with their sources. Advances in text-mining allow to work with “big data,” i.e. practically limitless amounts of text, and to ask research questions which have been unthinkable before. A number of historians working with “big data” in English are actively exploring these techniques trying to establish basic principles of digital analysis of historical documents of different kind. The field of pre-modern Islamic history still largely remains outside of digital history, to a certain extent because of the technical problems posed by the Arabic script. Yet, the historians of pre-modern Middle East are blessed (and probably cursed as well) to have a huge number of chronicles and biographical dictionaries. Because of their quite formulaic language, these sources can be effectively studied with scripting programming languages commonly employed in text-mining (e.g., Python). Using “Regular Expressions” --- a powerful tool that allows to manipulate pieces of text that conform to specific patterns, these sources can be mined for specific kinds of information (names, dates, secular professions, religious specializations and affiliations, toponymic data etc.), creating rather detailed profiles from each biographical entry. Sociological analysis of such biographical profiles in large quantities will allow to take a novel look at the social history of pre-modern Muslim world. Spatial and temporal analysis of even a rather limited amount of biographical characteristics will allow to trace a number of significant historical developments in time and space, e.g., the formation and spread of legal schools, development of different disciplines of religious learning, correlations between “secular” occupations of the learned and their geographical origins, the formation and shifting of centers of religious learning, etc. My paper will address some important theoretical issues of such digital analysis and will be focused on preliminary results of my analysis of al-Dhahabi’s Ta’rikh al-Islam, one of the biggest historic-biographical works, which covers 700 years of Islamic history and contains over 25,000 biographical entries.