The present paper,delineating the history,in which the Byzantine Empire and Ostrogothic Kingdom com-pletely broke with each other,concludes that this breakdown should be attributed to the collapse of the government headed by Amalasuntha,who adhered to the pro-Byzantine policy.The reason why the origi-nal policy was abandoned lay in some Ostrogothic aristocrats treating the Byzantine as their enemy.This change,as the paper argues,prepare an opportunity for the Byzantine Empire to reshape the Mediterra-nean world.