In the fourth century, the Roman emperor Constantine legalized Christianity, and by the fifth century it was the official religion of the empire. This change transformed the previously illegal and persecuted religion into the most important cultural force throughout the Mediterranean world. While Christian devotion flourished during the fifth century, the Roman Empire at large began to disintegrate. Rome was sacked twice, and by the end of the century the western portion of the empire was in the hands of Germanic-speaking Christian peoples such as the Goths, Lombards, and Franks. These usurping kingdoms encouraged the spread of Christianity into new territories, such as Saxony in modern Germany. Despite Rome’s loss of the western Mediterranean, the eastern part of the empire, called the Byzantine Empire by modern scholars, endured until the Ottoman Turks captured Constantinople in 1453.