The four Byzantine historians of 'the Fall' of the Byzantine Empire, Doucas Chalcocondyles, Sphrantzes and Critobulos, as well as the Byzantine short chronicles, bring many news concerning Serbian history of the first half of the XV century. Although almost all of them refer to the Serbian political history of the period, they also imply that Serbia was a state, having its own territory, ethnicity, government, diplomacy, army and economic resources.