Leo III managed a ruse to turn the Siege of Constantinople, during 717-718, in his favor and won an important victory against the Arabs at the Battle of Akroinon in 740. To win he used Greek Fire in combination of his military genius. He also reorganized the themes in Anatolia. Constantine V, son of Leo III, won noteworthy victories and invaded Syria. The Battle of Keramaia resulted in a major Byzantine naval victory.

The 8th and 9th centuries were dominated by religious unrest due to iconoclasm, a period where icons were destroyed for religious or political reasons. Icons were banned by Leo II and Constantine V. Icon-worshipers revolted. In 787 it was decided that icons should be revered, but not worshiped. Iconoclasm ensured that east and west became even further apart from each other. Empress Irene tried to arrange a marriage between Charlemagne and herself.

The accession of Basil I to the throne in 867 marks the beginning of the Macedonian dynasty. This dynasty, for about 150 years, included some of the most able emperors in Byzantium’s history. The Empire changed from defending against external enemies to reconquest of lost territories. In addition to the military power and political authority, the Byzantine Empire knows a cultural revival in spheres as philosophy and the arts. There was a conscious effort to restore the glory of the Roman Empire. This era has been dubbed the "Golden Age" of Byzantium. Due to the renewed security, cities expanded, populations grew and production increased. There was a boosting demand for goods and trade. In the cultural field, education knew an improvement. Ancient texts had to be preserved and were copied with great patience. The art flourished and mosaics adorned the many new churches.

Although the Empire was smaller than during the reign of Justinian, it regained much strength, as the remaining territories were less dispersed and more politically, economically and culturally integrated.

The Byzantine Empire flourished under the Macedonian dynasty. The city of Constantinople became the largest and wealthiest city in Europe. During this period, the empire employed a strong civil service staffed by competent aristocrats that oversaw the collection of taxes, domestic administration and foreign policy. The Empire’s wealth increased by fostering trade with Western Europe, particularly though the sale of silk and metalwork.

Due to the renewed security, cities expanded, populations grew and production increased. There was a boosting demand for goods and trade. In the cultural field, education knew an improvement. Ancient texts had to be preserved and were copied with great patience. The art flourished and mosaics adorned the many new churches. The church began to support the Emperor’s policies and the power of the landowners was limited to protect the small farmers. The farmers were an important part of the Empire’s military strength. This was a good condition to make war on the Arabs.

In 1054, relations between the eastern and Western traditions reached its peak in a terminal crisis. The Byzantine Empire fell into a period of difficulties caused by a large extent by the determining of the theme system and the neglect of the military. The army of professional career soldiers became dependent on foreign mercenaries, who were expensive. The need for maintaining large garrisons and expensive fortifications was receding too. Incompetent efforts to revive the Byzantine economy resulted in severe inflation and debased gold currency. The army became a political threat and unnecessary expense. At the same time, new enemies appeared in southern Italy, the Normans. These warriors from the north advanced, slowly but steadily into Byzantine Italy.

Under the Komnenoi, the Empire played a major role in the history of the Crusaders in the Holy Land, which Alexios I had helped bring about. The contact between Byzantium and the ‘Latin West’, including the Crusader states, increased significantly during this period. Venetian and other Italian traders became resident in large numbers in Constantinople. Their presence helped spread the Byzantine technology, art, literature and culture throughout the Latin West. In the meantime leading Western ideas and customs in the Byzantine Empire. Alexios I faced a immense attack by the Normans under Robert Guiscard, who died in 1085, which temporarily resolved the Norman problem. The following year, the Seljuq sultan died too, which resolved an other problem. Stability returned in the Empire, so Alexios I could put his mind to the severe economic difficulties and disintegration of the traditional defenses.

At the Council of Piancenza in 1095, Alexios I spoke to Pope Urban II about the suffering of the Christians of the East, and that without help from the West, they would continue to suffer under Muslim rule. The Pope saw the request as a dual opportunity to cement Western Europe and reunite with the Eastern-Orthodox Church with the Roman Catholic Church under his rule. At the Council of Clermont, all those present were urged by the Pope to take up arms under the sign of the Cross and launch an armed pilgrimage to recover Jerusalem from the Muslims. Immense and undisciplined forces arrived in Byzantine territory, with four of the eight leaders being Normans, among the son of Robert Guiscard. Alexios required its leaders to swear to restore all territories they might reconquer from the Turks on their way to the Holy Land. Crusaders became vassals for Alexios in 1108.

Manuel I Komnenos, grandson of Alexios I; made several alliances with the Pope and Western Kingdoms and he successfully handled the passage of the Second Crusade through his empire. However, in 1176 at the Battle of Myriokephalon against the Turks, he suffered a major defeat.

Andronikos I Komnenos, a grandson of Alexios I, took the power in 1182 after a coup d’état, when Manuel died in 1080. He eliminated all his rivals and let himself crowned as co-emperor. He was determined to root out corruption. The aristocrats were infuriated against him, and it seemed almost that Andronikos seek to exterminate aristocracy. It did not end well for Manuel.

In 1198, Pope Innocent III broached the subject of a new crusade with the intent to conquer Egypt, the center of Muslim power at the time. The crusader army arrived in Venice in 1202 and let them transport to Egypt. As payment they captured the Christian port of Zara. Alexios Angelos, son of the blinded Emperor Isaac II made contracts with the crusaders. He offered to reunite Byzantine Church with Rome, pay them, join he crusade and provide all supplies they needed to reach Egypt. The crusaders arrived at Constantinople in 1203 and quickly attacked. Alexios Angelos, son of the deposed blinded emperor was elevated to the throne as Alexios IV, along with his blinded father Isaac, but not for long. In 1204 the crusaders retook the city and Constantinople was subjected to pillage and massacre by the rank and file for three days. When order restored, the crusaders and the Venetians proceeded their agreement, Baldwin of Flanders was elected and elected emperor of a new Latin Empire. The lands divided up among the leaders.