Which aspect of the roman empire continued into the byzantine empire

The need for fighting off invading groups.

Explanation:

Byzantine Empire came into existence after the fall of the Roman Empire. The major contribution of the empire was to preserve the Greek language and culture as well as the Romans. The necessity to fight the enemies and stop them from invading remains the same in both Empires. Both empires built on the strong military, which helped them to rule over Europe and expand its territories. Byzantine Empire ruled most of Eastern and Southern Europe.

the romans were initially interested in expansion via sicily (which at that time was a cultural melting pot), part of which lay under carthaginian control. at the start of the first punic war (264-241 bc), carthage was the dominant power of the western mediterranean, with an extensive maritime empire