L'autorit\ue0 del 'basileus' nel confronto con i Latini

The first section of this paper draws a picture of the situation between the two sides of the medieval world. In the 9th century the empire, which the Byzantine considered the empire they had received from the Roman, was separated from its Western territories and decreased by half: it became the Greek empire, at least in the eyes of the Latins. This study recalls the Latin and Greek sources which show the progressive appearing of the new situation and the increase of political polemics, which were also connected to religion, different institutional development and customs. Since the end of 11th century crusades and commerce caused an increase of the relations between the two parts of the medieval world despite the growth of reciprocal mistrust. The aim of the second section of this paper is to show how the Latins, due to their widespread presence in the empire, to their services and to the bonds with the emperors, could be involved in the civil wars and influence consent and dissent to the autocrat weakening his power