Which empire is referred to in this quote Western Europe owed a debt of gratitude to the empire for that almost a thousand years ensued the survival of Christianity during a time when Europe was to we?

The quote refers to the Byzantine Empire, which played a crucial role in preserving and protecting Christianity during the Middle Ages. After the fall of the Western Roman Empire, the Byzantine Empire served as a bastion of Christian culture and learning, safeguarding religious texts and traditions. Its influence helped shape the development of Western Christianity, particularly through its interactions with both the Eastern Orthodox Church and the Roman Catholic Church.