OCR GCSE History B (J411) — The First Crusade (c.1070–1100)
It is much easier for invaders to breach a mighty fortress if the guards inside are busy fighting each other. This was the tragic reality for the Byzantine Empire after the death of Emperor Basil II in 1025. Without a clear line of succession, the empire plunged into a period of severe dynastic instability where 13 different emperors violently seized control over just 56 years.
The political elite fractured into two bitter factions: the civilian bureaucracy in Constantinople and the provincial military aristocracy. These groups frequently launched military coups, known as usurpation, which pulled provincial armies away from the borders to fight in civil wars. Because the frontiers were left unguarded, external enemies found it incredibly easy to raid Byzantine territory, meaning this internal anarchy acted as the fatal pre-condition for later foreign invasions.
Understanding religious differences explains why the Byzantines were left entirely isolated when they desperately needed military aid from the West. In 1054, tensions between the Eastern Orthodox Church and the Roman Catholic Church reached a breaking point over the Pope's claim to supreme authority. The Byzantines firmly believed the Pope was only the "first among equals" and that their Emperor held ultimate earthly power.
This disagreement culminated in The Great Schism, a formal institutional separation triggered when papal representatives placed a bull of excommunication on the altar of the Hagia Sophia. The two halves of Christendom severed ties over theological disputes, including the Western use of unleavened bread (azymes) and changes to the Nicene Creed. Politically, this split was disastrous because Western monarchs were now highly reluctant to send troops to defend Greeks they viewed as heretics.
How does a massive superpower lose its ability to feed its people and recruit soldiers in a single afternoon? This nightmare became a reality at the Battle of Manzikert in August 1071, when Emperor Romanos IV Diogenes led an army against the . The Seljuks were a nomadic Sunni Muslim power expanding rapidly from Central Asia, utilising highly effective light cavalry horse-archers.
The battle resulted in a catastrophic Byzantine defeat caused by fatal tactical errors and brutal political betrayal. Romanos fatally divided his forces before the conflict, and his reserve commander deliberately led troops away to ensure the Emperor's downfall. The Seljuks used a "feigned retreat" tactic to draw the remaining Byzantines into deadly ambushes, resulting in Romanos becoming the first Byzantine emperor captured alive by a Muslim commander.
Following the defeat, the Seljuks permanently occupied Anatolia (Asia Minor), establishing the independent Sultanate of Rum. Because Anatolia was the empire's traditional "breadbasket" and primary source of tax revenue, its loss permanently crippled Byzantine military capacity.
Whenever a government relies entirely on expensive private contractors rather than its own citizens, its treasury quickly drains. Following the loss of Anatolian recruiting grounds, the traditional Thematic System of peasant-soldiers completely collapsed. To defend their shrinking borders, emperors became entirely reliant on expensive foreign troops, leading to a dangerous cycle of mercenary dependence.
To pay for elite units like the Varangian Guard, the government resorted to severe currency debasement. They stripped the gold out of the traditional nomisma coin, heavily damaging the empire's economic credibility until Emperor Alexios I successfully reformed the currency with the pure gold hyperpyron in 1092.
The empire also sacrificed its long-term financial independence to secure immediate military help. To gain naval support from Italian city-states like Venice, emperors granted them massive trade monopolies and tax breaks. These concessions starved Constantinople of crucial trade taxes, creating an economic strangulation that severely weakened the state.
It is deeply shocking to consider that the fatal strike against the Byzantine Empire came from fellow Christians sent to help them. By the early 13th century, the empire was completely encircled by hostile powers like the Seljuks in the East and Normans in the West. Seeking to exploit this weakness, Venetian Doge Enrico Dandolo diverted the Fourth Crusade toward Constantinople to collect massive financial debts owed by a Byzantine prince.
In April 1204, the Crusaders breached the walls and subjected the capital to a brutal sack, looting staggering amounts of silver and sacred relics like the Crown of Thorns. The Crusaders divided the conquered lands among themselves, establishing a feudal Catholic state known as the Frankokratia.
The old empire shattered into three fragmented Greek successor states. While the Byzantine Empire had historically acted as a crucial buffer protecting Western Europe from Islamic expansion, this crusade permanently shattered that shield.
Students often describe the Battle of Manzikert as a total conquest of the empire by the Seljuk Turks. In reality, it was a devastating defeat, but it was the internal Byzantine civil wars immediately after the battle that allowed the Turks to permanently settle in Anatolia.
When answering 'Explain' questions about the Byzantine decline, examiners expect you to establish a clear causal chain; for example, explicitly link the loss of Anatolia at Manzikert to the later economic collapse caused by mercenary dependence.
Always mention Emperor Alexios I Komnenos when discussing the empire's temporary recovery; his introduction of the hyperpyron coin and family-based government briefly reversed the political decay.
Use the concept of 'religious pressure becoming political pressure' when discussing the Great Schism, as the label of 'heretic' gave Western powers a convenient excuse to ignore Byzantine calls for help or attack them directly.
Dynastic instability
Political chaos where the ruling family's right to lead is constantly challenged, resulting in frequent coups and civil wars.
Bureaucracy
The complex administrative system of officials in Constantinople that frequently clashed with the military elite over state funding.
Usurpation
The act of illegally taking the throne by force, which was common due to the lack of formal Byzantine succession laws.
The Great Schism
The formal institutional separation in 1054 between the Eastern Orthodox Church and the Roman Catholic Church.
Excommunication
The religious punishment of excluding someone from Church sacraments, effectively cutting ties between Eastern and Western Christians in 1054.
Azymes
The Western Christian practice of using unleavened bread for communion, which was heavily condemned by the Eastern Church.
Battle of Manzikert
A decisive 1071 conflict where the Seljuk Turks crushed the Byzantine army and captured Emperor Romanos IV.
Seljuk Turks
A nomadic Sunni Muslim power from Central Asia that relied on light cavalry and horse-archers to conquer Byzantine territory.
Anatolia (Asia Minor)
The region that served as the Byzantine empire's 'breadbasket,' providing its main source of grain, tax revenue, and military recruits.
Sultanate of Rum
The independent Islamic state established by the Seljuk Turks in Anatolia following their victory at Manzikert.
Thematic System
The traditional Byzantine military system where peasant-soldiers were granted land in exchange for their military service.
Mercenary dependence
The dangerous shift from relying on a national army of citizens to hiring expensive, often unreliable foreign troops.
Varangian Guard
An elite unit of the Byzantine army made up of hired foreign mercenaries, primarily from Northern Europe.
Nomisma
The traditional gold coin of the Byzantine Empire, which was severely debased to pay for foreign mercenaries.
Hyperpyron
A new, highly pure gold coin introduced by Emperor Alexios I in 1092 to restore economic trust and stability.
Enrico Dandolo
The Doge of Venice who manipulated and diverted the Fourth Crusade to attack Constantinople for Venetian financial gain.
Frankokratia
The period of Latin and Western European rule established over former Byzantine territory after the 1204 sack of Constantinople.
Put your knowledge into practice — try past paper questions for History B
Dynastic instability
Political chaos where the ruling family's right to lead is constantly challenged, resulting in frequent coups and civil wars.
Bureaucracy
The complex administrative system of officials in Constantinople that frequently clashed with the military elite over state funding.
Usurpation
The act of illegally taking the throne by force, which was common due to the lack of formal Byzantine succession laws.
The Great Schism
The formal institutional separation in 1054 between the Eastern Orthodox Church and the Roman Catholic Church.
Excommunication
The religious punishment of excluding someone from Church sacraments, effectively cutting ties between Eastern and Western Christians in 1054.
Azymes
The Western Christian practice of using unleavened bread for communion, which was heavily condemned by the Eastern Church.
Battle of Manzikert
A decisive 1071 conflict where the Seljuk Turks crushed the Byzantine army and captured Emperor Romanos IV.
Seljuk Turks
A nomadic Sunni Muslim power from Central Asia that relied on light cavalry and horse-archers to conquer Byzantine territory.
Anatolia (Asia Minor)
The region that served as the Byzantine empire's 'breadbasket,' providing its main source of grain, tax revenue, and military recruits.
Sultanate of Rum
The independent Islamic state established by the Seljuk Turks in Anatolia following their victory at Manzikert.
Thematic System
The traditional Byzantine military system where peasant-soldiers were granted land in exchange for their military service.
Mercenary dependence
The dangerous shift from relying on a national army of citizens to hiring expensive, often unreliable foreign troops.
Varangian Guard
An elite unit of the Byzantine army made up of hired foreign mercenaries, primarily from Northern Europe.
Nomisma
The traditional gold coin of the Byzantine Empire, which was severely debased to pay for foreign mercenaries.
Hyperpyron
A new, highly pure gold coin introduced by Emperor Alexios I in 1092 to restore economic trust and stability.
Enrico Dandolo
The Doge of Venice who manipulated and diverted the Fourth Crusade to attack Constantinople for Venetian financial gain.
Frankokratia
The period of Latin and Western European rule established over former Byzantine territory after the 1204 sack of Constantinople.
