What empire is given credit for preserving Greek and Roman culture and defending the west from invasion?

The Byzantine Empire is credited with preserving Greek and Roman culture, particularly during the Middle Ages. It maintained classical knowledge through its libraries, schools, and the continued use of Greek and Latin languages. Additionally, the Byzantine Empire played a crucial role in defending Western Europe from invasions, particularly from various tribes and the rising power of the Islamic Caliphates. Its influence helped shape the cultural and political landscape of Europe during and after its existence.