The study investigates Greek and Ottoman archival material, and presents to the reader hitherto unexplored aspects of the history of Nicosia during the last century of Ottoman rule on the island. It also clarifies issues concerning its history in earlier centuries, reaching as far back as 1571, the year of its submission to the Ottomans. Consequently, it lays new foundations for a critical reevaluation of some opinions that have been prevalent until now regarding the topography of the city (the number and names of its districts), the history of the ethnoreligious communities (Greeks, Turks, Armenians, Maronites) that habitated the city, already from the Frankish and Venetian era. The first volume is a historical study that exposes the reader to the research results of a systematic treatment of the population catastrophes of the Ottoman period, which are presented with rich annotation in the two following volumes of the work. The Greek and Ottoman sources published there make accessible valuable material for anybody interested in studying thus far unexplored topics related to the history of Cyprus.