Final answer:
The Byzantine Empire was characterized by centralized imperial power, with the emperor acting as God's representative, and a sophisticated diplomatic approach to managing both internal elite challenges and external threats.
Step-by-step explanation:
The feature of the Byzantine state that best describes its governance is 'The emperor claimed to be God's representative on earth.' This is reflective of the central role the emperor played in both the political and religious spheres of the empire. The Byzantine Empire faced numerous external threats and internal challenges through its history. Its emperors, such as Justinian, attempted to preserve the unity and strength of the empire. Aggressive diplomacy, intelligence gathering, and negotiation were key aspects of its foreign policy, while internally, legislation was at times used to reduce the power of the elite dynatoi who sought to undermine the authority of the emperor.