From the mid ninth to the early eleventh century, under the Macedonian dynasty, the Byzantine Empire enjoyed a revival in power, learning and art. Then, within a few decades, it faced crises that would draw Western crusaders into its affairs, with fateful consequences.

The Macedonian revival

The dynasty founded by Basil I in 867 ruled for nearly two centuries. Byzantine armies recovered territory in the east. Scholarship flourished in a period sometimes called the Macedonian Renaissance. The patriarch Photios, one of the most learned men of the age, compiled the Bibliotheca, summaries of hundreds of books he had read, many of which are now lost and known only through his notes. Scholars copied ancient Greek texts, preserving works of Plato, Aristotle and others that might otherwise have vanished. The emperor Constantine VII wrote or sponsored works on ceremony, administration and foreign peoples.

Basil II

The greatest Macedonian emperor, Basil II, ruled from 976 to 1025. After long wars, he conquered the Bulgarian state. In 1014, after the Battle of Kleidion, according to a later chronicle, he blinded about fourteen or fifteen thousand Bulgarian prisoners, leaving one man in every hundred with one eye to lead the others home. The Bulgarian ruler, Samuel, is said to have died of shock at the sight. Some historians think the numbers were exaggerated, but the story earned Basil the nickname “Bulgar-slayer.” By his death, the empire was at its greatest extent since Justinian's time.

The gold coin

The empire's wealth rested on a stable currency. The gold coin known as the solidus, called the nomisma in Greek and the bezant in the West, introduced by Constantine, kept nearly the same gold content for about seven hundred years, an extraordinary record. It was trusted across the Mediterranean and beyond, and has been called the dollar of the Middle Ages. In the eleventh century, under financial pressure, emperors began to debase it.

Women in power

Byzantine women could hold real power, usually as empresses, regents or members of the imperial family. In 1042, after the people of Constantinople rose against an emperor who had exiled the popular empress Zoe, Zoe and her sister Theodora ruled together for a short time, a rare case of two women governing jointly in their own right.

The schism of 1054

For centuries, the churches of Rome and Constantinople had drifted apart over language, customs, theology and authority. A key question was whether the pope had supreme authority over the whole church, as Rome claimed, or was the first among equal patriarchs, as the East held. In 1054, a papal legate, Cardinal Humbert, and the patriarch of Constantinople, Michael Keroularios, excommunicated each other. The event is traditionally seen as the beginning of the Great Schism between the Catholic and Orthodox churches, though at the time it seemed one quarrel among many. The mutual excommunications were formally lifted only in 1965.

Manzikert

After Basil II's death, weaker rulers, court struggles and neglect of the army undermined the empire. In 1071, the Seljuk Turks, a new power from Central Asia, defeated the Byzantine army at the Battle of Manzikert in eastern Anatolia, and captured the emperor Romanos IV. The battle itself was less decisive than the civil wars that followed, which let Turkish groups move into Anatolia, the empire's heartland. Within a few years, much of Anatolia was lost.

Alexios Komnenos and the call to the West

Alexios I Komnenos, who seized power in 1081, set about restoring the empire. Needing soldiers, he asked the pope for help in recruiting Western mercenaries. Pope Urban II, in a sermon at Clermont in France in 1095, went much further, calling on Western Christians to march east, help their fellow Christians and liberate Jerusalem. The result was the First Crusade, which took Jerusalem in 1099 amid massacres of its Muslim and Jewish inhabitants. The crusaders also set up their own states in the east rather than returning lands to Byzantium, as Alexios had expected, and relations soured.

Our main source for Alexios's reign is the Alexiad, a history written by his daughter, Anna Komnene, one of the first known women historians. She described the crusaders with a mixture of fascination and alarm.

Worked example: the unintended consequences of asking for help

Trace how Alexios's appeal for help produced outcomes he did not intend.

1. The request. Alexios wanted a limited number of mercenaries to fight the Turks under his command.
2. The response. The pope turned it into a mass religious movement with its own goal, Jerusalem.
3. The arrival. Tens of thousands of crusaders, not all disciplined, arrived at Constantinople, alarming the Byzantines.
4. The result. The crusade recovered some Anatolian territory for Byzantium, but the crusaders kept other conquests and grew suspicious of the Greeks.
5. The long term. Mistrust between Byzantines and Westerners deepened, eventually leading to the disaster of 1204.

Alliances with powerful outsiders can bring help, but they also bring the outsiders' own goals. Leaders who seek help must ask not only whether it will solve their immediate problem but what their allies want, and what will happen when those wants conflict with their own.