How did the struggle against external danger influence the development of Byzantium?

Byzantium had many enemies on all borders. To ensure the security of its country and the advantage over opponents, the government had to change the structure of the army and the country itself. So, for better resistance to invasions, territorial entities, the so-called femas, arose on the territory of Byzantium in order to distribute troops throughout the empire and be able to quickly assemble them for war. Tactics are also changing – instead of heavily armed infantry, cavalry comes out on top. The technique of sieges is developing. The most important invention of the Byzantines is the Greek fire. For the sake of helping in the war, Byzantium guaranteed financial benefits to those states that responded to the call, which ultimately led to a weakening of the empire’s trade.