The eastern part of the Roman Empire held imperial power led by the city Byzantium later renamed Constantinople in honor of Emperor Constantine (316). It remained the capital until Charlemagne revived the Western Empire (316). Between 324 and 330, “the Byzantine Empire moved from an early period of expansion and splendor to a time of sustained contradiction and breakup and, ultimately, catastrophic defeat” (316). The first period; between 324 and 632, Byzantine history experienced great successes on the territorial, political and cultural levels (317). Above all, during the reign of Emperor Justinian and Empress Theodora; both intelligent and tough; even to the point of being described as tyrants by their court historian and biographer (317-18). During their reign there were over 1,500 cities, Constantinople being the largest, full of grandeur and splendor (317). Between the 4th and 5th centuries, the Decurions; councils of 200 wealthy local landowners governed the towns (318). However, in the 6th century, the councils of decurions were replaced by special governors deemed more reliable by the emperor (318). Justinian also ordered a revision of Roman law and created several compilations with the help of a committee of learned jurists (320, 342). These compilations later became the basis of most European laws (320). The first compilation; Code, revised imperial edicts, the second; Novellae, presented the decrees issued by Justinian and his successors, the third; the Digest, compilation of old opinions of legal experts, and the fourth compilation; Institutes, a practical manual for young researchers (320). However, this strengthening of the empire did not allow it to recover the western imperial lands conquered by the barbarians...... middle of paper ...... their religion over the people (325). Thus, these people found refuge with the Muslims against Byzantine oppression (325). Muslim conquerors tolerated other religions and offered protection to many peoples (326). Christian Europe developed a lasting fear and suspicion of Muslims as they were attacked and challenged on all fronts (326). In both the east and the west, the Muslim invasion was confronted and stopped although contacts between Muslims and Christians continued (326). Muslims viewed Byzantium “as a model from which one could learn and improve” (326). Despite the differences between the Christian West and the Muslim world, there were creative exchanges between the two (326). Since the Arabs were more advanced, it was the West that benefited the most from these exchanges (326). Often the Church became an important force for Western Europe through invasions, changes, etc.. (328).