hroughout the Ottoman period, the plains around the long rivers in the Balkans were crucial to the empire's taxation policy. This was so because the land is so fertile that it covered the needs of the big cities, and most importantly, those of the capital itself. The financial services of the state kept detailed records of agricultural production in Macedonia and Thrace, which were updated at regular intervals, at least until the 17th century. The emphasis was on wheat production in the Strymonas, Nestos and Axios valleys, and east of the Evros, because it was these areas which provided a considerable proportion of the food supplies for Constantinople, and almost all the provisions for large cities such Adrianopolis (Edirne) and Thessaloniki.
