How to divide the period
Byzantine history is usually divided into three broad phases: an early period of late antiquity, a middle period of contraction and recovery, and a late period of decline. Historians draw the lines in slightly different places, and the dates below are approximate. The goal is to give a framework, with each phase kept short, so that the details found elsewhere have somewhere to fit.
Early period, about 500 to 700
Background. Constantinople was dedicated in 330. After the fall of Rome in the West in 476, the eastern emperors remained in power and kept Roman institutions, the Greek language and Christian faith at the center of the state.
527-565, Justinian. The emperor’s armies reconquered North Africa, Italy and a corner of Spain. His legal compilation and the construction of Hagia Sophia date to this reign. The cost was high, and the great plague that began in the 540s weakened the population.
Late 500s. Slavs and Avars moved into the Balkans, and war with Persia flared again.
610-641, Heraclius. He took the throne during a crisis, and after a long war defeated Persia in the 620s. In the 630s and 640s Arab armies conquered Syria, Palestine and Egypt. By his death the empire had lost its richest eastern provinces.
Middle period, about 700 to 1070
Late 600s and 700s. The empire was reorganized into themes, military districts with local commanders. Arab sieges of Constantinople in the 670s and 717-718 were beaten off.
726-843. The iconoclast controversy divided the empire over religious images. The use of icons was permanently restored in 843.
800. The coronation of Charlemagne in the West as emperor created a rival imperial claim, which Constantinople resented. Relations with the Holy Roman Empire and its predecessors stayed uneasy for centuries.
860s-900s. Missionary activity among the Slavs, and a lasting dispute with the pope over authority, marked this time. The reigns of Basil I and his heirs, the Macedonian dynasty, began in 867.
900s. The empire went on the offensive in Syria, Crete and the Balkans. Constantine VII and others also encouraged scholarship, compiling encyclopedias and manuals.
976-1025, Basil II. He defeated rebel generals, conquered Bulgaria by about 1018 and used the Varangian Guard as his personal bodyguard. At his death the empire stretched from southern Italy to the Caucasus borderlands.
1054. A quarrel between papal envoys and the patriarch of Constantinople produced the mutual excommunications usually described as the start of the East-West schism. Historians stress that it did not feel like a final break at the time.
Late period, about 1070 to 1453
1071. At Manzikert, the emperor was captured by the Seljuk Turks. A series of civil wars followed, and Turkish groups moved into Anatolia.
1081-1180, the Komnenian era. Alexios I and his successors rebuilt the army and recovered coastal Anatolia. The first crusade arrived in 1096, and the relationship with crusaders and the Crusader States was often tense. After the defeat at Myriokephalon in 1176, the revival faded.
1204. A Western army diverted from its original aim took and sacked Constantinople. A Latin Empire ruled the city for about half a century, while Greek successor states held out in Nicaea, Epirus and Trebizond.
1261. Michael VIII Palaiologos recovered the city. The restored empire was weak, and the Palaiologan dynasty held on to the throne until the end.
1300s. Civil wars, the Black Death, Serbian expansion and the rise of the Ottomans gradually reduced the state. The Ottomans crossed into Europe in the 1350s. By the end of the century the emperors were paying tribute.
1402. The Ottoman sultan Bayezid I was defeated by Timur near Ankara, giving the empire a brief pause.
1439. The Council of Florence agreed on a union of the Eastern and Western churches, but it was widely rejected in Constantinople.
1453. After a siege of about seven weeks, Mehmed II took the city on May 29. The last emperor, Constantine XI, is believed to have died in the fighting.
1460-1461. The last Greek holdouts, the Morea and Trebizond, fell to the Ottomans.
Patterns that run through the timeline
Three themes recur. First, the empire’s survival depended heavily on Constantinople itself, whose defenses outlasted the provinces. Second, recoveries were usually led by capable rulers, and were fragile when they were not followed by stable succession. Third, the empire’s neighbors changed, from Persians and Arabs to Turks and Italians, but the state always had to cope with several fronts at once.
A note on terms
The people of the empire called themselves Romans, and their state the Roman Empire. “Byzantine” is a modern convenience. Dates for beginning the period vary: some historians start in 330, with Constantine, others in 395 when the empire was permanently divided, and others with Justinian or even later. That is why this timeline begins around 500 and treats earlier events only as background.