As the only stable long-term state in Europe during the Middle Ages, Byzantium isolated Western Europe from newly emerging forces to the East. Constantly under attack, it distanced Western Europe from Persians, Arabs, Seljuk Turks, and for a time, the Ottomans. From a different perspective, since the 7th century, the evolution and constant reshaping of the Byzantine state were directly related to the respective progress of Islam.
Some scholars focused on the positive aspects of Byzantine culture and legacy, French historian Charles Diehl described the Byzantine Empire by saying:
Byzantium created a brilliant culture, may be, the most brilliant during the whole Middle Ages, doubtlessly the only one existing in Christian Europe before the XI century. For many years, Constantinople remained the sole grand city of Christian Europe ranking second to none in splendour. Byzantium literature and art exerted a significant impact on peoples around it. The monuments and majestic works of art, remaining after it, show us the whole lustre of byzantine culture. That's why Byzantium held a significant place in the history of Middle Ages and, one must admit it, a merited one.