History | Causes and effects of wars (750–1500)

🌍 Causes and Effects of Wars (750–1500): Study Notes ⚔️

Hello Historians! This chapter dives into a truly vast and exciting period: the Medieval and early Renaissance eras. We’re moving beyond simple battle stories to understand the massive forces—political, religious, and economic—that drove societies across Afro-Eurasia to conflict between 750 and 1500.

Understanding causation (why wars start) and consequence (what happens next) is crucial for your IB exams. Don't worry if this seems tricky at first; we will break down the complexity using clear categories and powerful examples!

I. The Historical Context (750–1500)

This period marks the transition from the early medieval world into the late medieval/early modern era. Key features that fueled conflict included:

• Decentralization in Europe: The rise of Feudalism, where power was fragmented among kings, nobles, and local lords, leading to frequent internal struggles over land and loyalty.
• The Islamic Golden Age: Major empires (Abbasids, later Ottomans) expanded rapidly, clashing with Christian powers (Byzantium, Western Europe) and rival Islamic states.
• Nomadic Power: The immense military and political impact of nomadic groups, particularly the arrival of the Mongols in the 13th century.
• Technological Shift: The slow introduction of gunpowder and increasingly sophisticated siege technology.

II. Categorizing the Causes of War (750–1500)

Wars rarely have a single cause. Historians often look for multiple factors. Think of causes in four major categories (P.E.R.S.):

A. Political and Dynastic Causes

These causes relate to who holds the power and who rules the territory.

• Territorial Expansion: Rulers sought more land to increase wealth, taxation base, and prestige. Example: The Norman Conquest of England (1066) was primarily a dynastic and territorial grab.
• Succession Disputes (Dynastic Claims): When a ruler died without a clear heir, relatives often went to war to claim the throne. Example: A key cause of the Hundred Years’ War (1337–1453) was the English King's claim to the French throne.
• Maintaining Honour/Prestige: Demonstrating military might was essential for a ruler's legitimacy.

B. Economic Causes

Conflicts often centered on control over valuable resources or trade routes.

• Control of Trade Routes: Controlling key overland routes (like the Silk Road) or crucial waterways allowed states to levy taxes and accumulate massive wealth. Example: Conflicts over Mediterranean port cities were frequent among Italian city-states (like Venice and Genoa).
• Wealth and Plunder: War was often a profitable business. Soldiers and states benefited directly from looting (plunder) and seizing land and resources.
• Taxation Needs: Rulers might instigate external wars to rally support and justify raising taxes internally.

C. Religious Causes

Religion provided a powerful ideological justification for immense conflicts, allowing leaders to mobilize huge populations.

• Holy War Justification: Concepts like the Christian Crusade or Islamic Jihad provided moral legitimacy for conquest, often promising spiritual rewards for participation.
• Defense of the Faith: Conflicts fought to protect religious sites or established religious boundaries.

D. Social/Ideological Causes

• Population Pressures: If a region experienced high population growth and land scarcity, leaders might encourage military expansion to settle excess populations or find new resources.
• Feudal Obligations: In Europe, lords were legally bound to follow their direct superiors (suzerains) into battle, regardless of the underlying political reason.

III. The Nature and Conduct of War (750–1500)

How wars were fought defines their impact. The period saw major shifts in military organization and technology.

A. Military Organization and Manpower

• Feudal Levies (Europe): Armies were temporary, consisting of knights fulfilling their military service obligations. These armies were often small, highly specialized (heavy cavalry), and difficult to keep in the field for long periods.
• Professional and Mercenary Forces: As warfare grew more complex and protracted (especially the Hundred Years’ War), reliance on paid, professional soldiers (mercenaries) increased. This was expensive but resulted in better trained and more reliable forces.
• The Mongol Model: The Mongols revolutionized organization. Their armies were fast, centrally disciplined, and highly mobile, structured into units based on the decimal system (tens, hundreds, thousands). Loyalty was enforced personally by Chinggis Khan and his successors.

B. Technology and Tactics

1. Siege Warfare

Since most wealthy cities and castles had stone fortifications, sieges were frequent and lengthy.

• Catapults and Trebuchets: Massive siege engines capable of throwing heavy projectiles to smash walls or spread disease (by launching diseased corpses).
• Sapping and Mining: Digging tunnels under walls to collapse them.
• Did you know? Medieval siege engineers were crucial. They were often the highest paid non-noble personnel!

2. The Rise of Infantry and Missile Weapons

Heavy cavalry (knights) began to lose their dominance as infantry became more effective.

• The English Longbow: Demonstrated devastating effectiveness against French knights at battles like Crécy (1346) and Agincourt (1415), showing that well-trained missile troops could defeat expensive armored cavalry.
• Pikes and Spears: Used to form defensive squares against cavalry charges (e.g., Swiss infantry).

3. Gunpowder (A Game Changer)

Gunpowder technology, originating in China, began to spread West via the Mongols and trade routes.

• Cannons: Early cannons were slow and unreliable, but they became effective in breaching castle walls by the 15th century, fundamentally changing the architecture of defense and making old feudal castles obsolete.
• Handguns: Very primitive early firearms were starting to appear, though they were not widespread until later centuries.

IV. Case Study 1: The Crusades (1095–c.1291)

The Crusades offer an excellent example of a long-term conflict driven by religious ideology, political opportunity, and economic greed.

A. Specific Causes

• The Byzantine Plea: The Byzantine Emperor asked the Pope for military help against the Seljuk Turks (political/military cause).
• Papal Ambition: Pope Urban II saw the First Crusade (1095) as a chance to heal the schism between the Eastern and Western Churches and assert Papal authority over European rulers (political/religious cause).
• Religious Zealotry: Desire among commoners and knights to liberate the Holy Lands (Jerusalem) and gain spiritual salvation (religious cause).
• Land and Riches: Many younger sons of European nobles, who stood to inherit nothing under primogeniture laws, sought new titles and territories in the East (economic/social cause).

B. Effects and Consequences

1. Political Effects

• Failure to Unite Christianity: The Crusades ultimately widened the gap between the Eastern (Orthodox) and Western (Catholic) Churches, especially after the disastrous Fourth Crusade (1204) sacked Constantinople.
• Formation of Crusader States: Temporary establishment of European kingdoms in the Middle East (e.g., Kingdom of Jerusalem), which were unstable and required constant defense.

2. Economic and Cultural Effects

• Trade Boom for Italians: Italian city-states (Venice, Genoa, Pisa) supplied transportation, materials, and funds, leading to massive profits and monopolization of Mediterranean trade.
• Cultural Exchange: Crusaders brought back new knowledge, goods (spices, silk), and technology (especially advanced mathematics and philosophy) from the advanced Islamic world, helping spark the Renaissance in Europe.

V. Case Study 2: The Mongol Conquests (c. 1206–1350)

The Mongol expansion, beginning under Chinggis Khan, constitutes one of the largest and most rapid territorial conquests in history, affecting China, Persia, Russia, and Eastern Europe.

A. Specific Causes

• Chinggis Khan’s Unification: The initial campaigns were aimed at uniting the scattered nomadic tribes of Mongolia under a single, disciplined leadership (dynastic/social cause).
• Mandate of Heaven/World Conquest: The Mongol leaders believed they had a spiritual mandate (often referenced as the "Eternal Blue Sky") to conquer and rule the world (ideological cause).
• Need for Resources/Tribute: As the population grew, the Mongols required control over settled, resource-rich lands to provide goods and secure access to trade routes (economic cause).
• Retaliation: Early attacks on Khwarazm (Persia) were spurred by the murder of Mongol envoys and merchants—a direct political affront.

B. Effects and Consequences

1. Demographic and Social Effects

• Massive Destruction: The conquests resulted in enormous depopulation across Central Asia, Persia, and Russia due to massacres and famine. Cities like Baghdad (1258) were devastated.
• Shift of Power: The conquests permanently ended powerful dynasties (like the Abbasid Caliphate) and fragmented regions into smaller Khanates (e.g., the Golden Horde, Yuan Dynasty in China).

2. Economic and Cultural Effects (The Pax Mongolica)

• Security of the Silk Road: Paradoxically, once the initial wave of destruction subsided, the Mongol Empire secured and unified the vast trade routes from East to West. This period of stability (the Pax Mongolica) facilitated unprecedented trade and diplomatic travel (Example: Marco Polo).
• Technological Transfer: Essential Chinese inventions (like gunpowder, printing, and the compass) were rapidly transferred to the West during this period of secure travel.
• Spread of Disease: Unfortunately, the secure, fast travel of the Mongols also facilitated the rapid movement of the Black Death from Asia into Europe in the 14th century, a devastating unintended consequence.

VI. General Consequences and Long-Term Impacts

Wars in this period led to sweeping changes that laid the foundation for the early modern world.

A. Political and Governmental Changes

• Rise of Centralized States: Prolonged, expensive wars (like the Hundred Years’ War) forced kings to seek permanent taxation and maintain professional armies. This weakened the power of local nobles and strengthened the central monarchy.
• Formation of Nation-States: The concept of unified national identity began to solidify, especially as people fought against a common foreign enemy (e.g., French identity solidified against the English).
• Decline of Feudalism: As cash became more important than land service for warfare (due to mercenaries and expensive gunpowder), the feudal system broke down economically and militarily.

B. Economic and Social Consequences

• Stimulus to Specific Industries: War drove demand for mining, metallurgy, and weapons production (especially canons and armor).
• Demographic Instability: While the direct death toll was high, wars often led to famine and facilitated the spread of epidemics (as seen with the Mongol Conquests and the Black Death), causing massive, long-term population collapse in many regions.
• Changing Social Status: The traditional prestige of the heavily armored knight waned, replaced by the importance of highly skilled, disciplined infantry and artillery commanders.

You've made it through! Remember, when analyzing causes and effects, always look for the interconnectedness. A religious cause might have an economic effect, and a political consequence might accelerate a social change. Good luck with your revision!