Paper 2 anchor: Causes and effects of wars (750–1500) — Effects of war

· Exact topic/subtopic: Paper 2, World history topic 2: Causes and effects of wars (750–1500), Effects.
· Official IB focus: wars and conflicts “among or between communities” and military expansion in the medieval world; students must analyse causes, course/practices/outcomes, and especially consequences.
· Effects bullets to revise: conquest, boundary and dynastic changes; successes and failures of peacemaking; political impact: short-term and long-term; economic, social, religious and cultural changes; demographic changes and population movements.
· Main exam expectation: use specific conflicts as evidence, not general medieval warfare.
· Regional requirement: exam questions may require examples from two different regions. The IB divides examples into Asia and Oceania, Africa and the Middle East, Europe, and the Americas.
· Suggested examples are not compulsory: the IB list gives suggested examples only. Teachers may use others, but students should still revise wars that fit the syllabus categories clearly.
· Cross-regional warning: the Crusades (1095–1291) can be used in a regional context such as the Middle East, but not again as a separate European example in the same “different regions” answer.

What “effects of war” really means in IB essays

· This subtopic is not just “what happened after the war”. It asks how war reshaped power, redrew boundaries, changed dynasties, altered societies, and sometimes failed to produce stable peace.
· Strong answers separate short-term impact from long-term impact. Example: Norman conquest of England (1066) immediately replaced the English monarchy, but its long-term effects included new aristocratic landholding, castle-building, and a more centralized monarchy.
· Effects should be judged by extent, duration, and who was affected: rulers, elites, peasants, religious groups, merchants, women, displaced populations, or conquered peoples.
· The best essays connect effects to the nature of the war: dynastic wars often changed rulers and succession; territorial wars changed borders and administration; religious wars often affected identity, persecution, conversion, or cultural contact.

Conquest, boundary and dynastic changes

· Norman conquest of England (1066) — Europe: use this as a clear example of conquest producing dynastic change. William of Normandy replaced Harold Godwinson, creating a Norman ruling dynasty in England. In an essay, this proves that war could rapidly transform royal legitimacy and elite landholding.
· England and France at war (1154–1204) — Europe: useful for boundary changes and the decline of Angevin power. The conflict between Angevin kings and Capetian France contributed to French recovery of territories, especially under Philip II, strengthening royal authority in France.
· Hundred Years’ War (1337–1453) — Europe: use for long-term territorial and political change. The war ended with England losing most continental possessions except Calais, while France emerged more consolidated. This supports arguments that war could accelerate state centralization.
· Tepanec War with the Aztecs (1428–1430) — Americas: use as a non-European example of war producing new political dominance. The defeat of the Tepanecs enabled the rise of the Aztec Triple Alliance, showing how war could create or expand imperial systems.
· Toluid Civil War (1260–1264) — Asia and Oceania: use for dynastic fragmentation within the Mongol world. Instead of external conquest, this war shows that succession conflict could weaken imperial unity and divide authority.

The Bayeux Tapestry visually presents the Norman version of the events around 1066. It is useful for showing how conquest was remembered as a transfer of legitimacy from the Anglo-Saxon monarchy to Norman rule. Source

Political impact: short-term and long-term

· Short-term political effects usually include the removal of rulers, instability, rebellions, emergency taxation, or disputes over succession.
· Long-term political effects include stronger monarchies, new administrative systems, changed relations between ruler and nobles, or the collapse of imperial unity.
· Norman conquest of England (1066): short term, violent regime change; long term, a new Norman elite and stronger royal government. Use this to argue that conquest could create both disruption and consolidation.
· Hundred Years’ War (1337–1453): short term, repeated crises of royal authority and military pressure; long term, stronger French monarchy and weakened English claims in France. It can also be linked to later instability in England, including the Wars of the Roses (1455–1487).
· Wars of the Roses (1455–1487) — Europe: use for internal dynastic conflict. Its effects were less about foreign borders and more about royal authority, succession, and the destruction or weakening of noble factions.
· Great ‘Abbasid Civil War (809–813) — Africa and the Middle East: use for political fragmentation within a caliphate. It demonstrates how civil war could damage central authority even when the state survived.
· Byzantine–Seljuq Wars (1048–1308) — Europe / Asia and the Middle East context: useful for long-term political decline and frontier change. In essays, use the regional context consistently and focus on how prolonged warfare weakened Byzantine control and enabled Turkish expansion.

Maps of the Hundred Years’ War help students visualize why its effects were political as well as military: English-held territory contracted while French royal authority expanded. Use the map to support arguments about long-term territorial and state-building consequences. Source

Peacemaking: successes and failures

· IB expects students to judge whether settlements produced lasting stability or merely paused conflict.
· Successful peacemaking is not the same as military victory. A ruler may win a battle but fail to secure a stable settlement.
· The Crusades (1095–1291): use as a strong example of repeated failed peacemaking. Treaties and truces sometimes paused conflict, but the survival of crusader states remained insecure, ending with the fall of Acre (1291).
· Hundred Years’ War (1337–1453): useful because temporary truces failed to resolve dynastic and territorial claims. The deeper issue — English claims to French territory and the French crown — made lasting peace difficult until the balance of power changed decisively.
· England and France at war (1154–1204): use to show how peacemaking could fail when rulers’ dynastic lands overlapped with royal authority. Settlements were fragile because the same territories had both feudal and royal significance.
· Toluid Civil War (1260–1264): useful for arguing that peacemaking can fail at the imperial level when rival claimants cannot accept a single succession settlement.
· Exam judgement: do not simply say “peace failed”. Explain why: unresolved claims, weak enforcement, religious hostility, dynastic rivalry, or lack of a mutually accepted authority.

The map of the Crusader states shows why peacemaking in the eastern Mediterranean was fragile: these states were geographically exposed and surrounded by rival powers. It supports analysis of why the Crusades produced repeated truces rather than lasting settlement. Source

Economic effects of war

· War could damage economies through destruction, disrupted trade, taxation, ransom, and military expenditure, but it could also redirect resources or strengthen states that controlled trade routes.
· Hundred Years’ War (1337–1453): useful for the economic burden of prolonged warfare. Repeated campaigns required taxation and military finance, contributing to pressure on both English and French societies.
· Norman conquest of England (1066): use for redistribution of land and resources. Conquest transferred wealth to Norman followers and changed patterns of lordship, showing that economic effects often followed political conquest.
· Crusades (1095–1291): use for mixed economic effects. War disrupted regions but also increased contacts between the Mediterranean, Europe, and the Middle East. In an effects essay, this supports a balanced judgement: destructive war could still intensify trade and cultural exchange.
· Mongol-related conflicts, including Toluid Civil War (1260–1264): use cautiously for economic consequences of imperial fragmentation. Mongol rule could protect routes, but civil war undermined unity and therefore weakened the political conditions that supported long-distance exchange.
· Tepanec War with the Aztecs (1428–1430): useful for tribute-based economic change. Victory enabled the Aztec alliance to expand extraction of tribute, showing that war could create new systems of economic dominance.

Social, religious and cultural changes

· IB expects more than political consequences. Always ask: how did war change communities, identities, beliefs, and cultural contact?
· Crusades (1095–1291): strongest example for religious and cultural impact. Use in the Middle East context to discuss religious conflict, crusader states, Muslim responses under leaders such as Nur al-Din, Saladin, and Baibars, and cross-cultural contact.
· Norman conquest of England (1066): use for social and cultural change: replacement of elites, French-speaking aristocracy, castle-building, and new ruling culture. The effect was not only dynastic; it changed how power was displayed and administered.
· Byzantine–Seljuq Wars (1048–1308): use for religious and cultural frontier change between Christian Byzantine and Muslim Turkish powers. Avoid turning this into a generic “clash of civilizations”; link it to political control, settlement, and frontier societies.
· Great ‘Abbasid Civil War (809–813): use for religious-political legitimacy. Civil war within a caliphate could weaken the symbolic unity of Islamic rule and intensify factional divisions.
· Tepanec War with the Aztecs (1428–1430): use for social hierarchy and tribute. War helped elevate the Aztecs from subordination to dominance, affecting subject peoples through tribute and imperial expansion.

The Mongol Empire map helps explain why civil wars such as the Toluid Civil War (1260–1264) mattered: the issue was not only succession, but control over a vast multi-regional empire. It supports analysis of dynastic fragmentation, regional khanates, and the weakening of unified imperial authority. Source

Demographic changes and population movements

· Demographic effects include death, displacement, migration, enslavement, settlement by conquerors, and the movement of elites or armies.
· Norman conquest of England (1066): use for elite demographic change rather than mass population replacement. The key effect was the arrival of a Norman ruling class and redistribution of land.
· Crusades (1095–1291): use for military migration, settlement, and displacement in the eastern Mediterranean. Crusader states created new ruling communities, while warfare repeatedly displaced local populations.
· Mongol conflicts: useful for population movement and destruction, especially where conquest or civil conflict disrupted settled societies. For Paper 2, keep the focus on specific wars from the syllabus list, such as the Toluid Civil War, rather than drifting into a general Mongol Empire narrative.
· Hundred Years’ War (1337–1453): use for disruption of civilian life, ravaging, insecurity, and movement away from war zones. Link demographic effects to economic and political consequences.
· Exam judgement: demographic effects are often hardest to quantify for medieval wars, so use them as part of a broader argument unless you have precise evidence.

Compact evidence bank: best examples for essays

· Norman conquest of England (1066), Europe — demonstrates conquest, dynastic change, elite replacement, and long-term political consolidation. Best for questions on political impact, social change, or conquest.
· Hundred Years’ War (1337–1453), Europe — demonstrates long-term territorial change, stronger French monarchy, weakened English position in France, and financial/social strain. Best for questions on short-term vs long-term effects.
· Wars of the Roses (1455–1487), Europe — demonstrates effects of dynastic conflict on royal authority and noble power. Best for questions on political instability after war.
· Crusades (1095–1291), cross-regional but use in one regional context — demonstrates religious, cultural, political, and demographic effects; also useful for failed peacemaking. Best used as Middle East impact or Europe impact, but not both in one two-region answer.
· Toluid Civil War (1260–1264), Asia and Oceania / Mongol world — demonstrates succession conflict, dynastic fragmentation, and weakening of imperial unity. Best for questions on dynastic change and long-term political impact.
· Great ‘Abbasid Civil War (809–813), Africa and the Middle East — demonstrates internal civil war weakening central authority and damaging legitimacy. Best for questions on political impact and civil conflict.
· Byzantine–Seljuq Wars (1048–1308), Europe / Asia and Middle East frontier — demonstrates long-term boundary shifts, frontier transformation, and weakening of Byzantine power. Best for questions on territorial and religious-cultural consequences.
· Tepanec War with the Aztecs (1428–1430), Americas — demonstrates war as a turning point in imperial expansion and tribute extraction. Best for non-European comparison and economic/political effects.

The map helps students place the Tepanec War with the Aztecs (1428–1430) in a wider imperial context. It supports arguments that war could create new regional power structures and tribute systems in the Americas, not only in Europe or the Middle East. Source

How to compare effects across regions

· Europe vs Americas: compare Norman conquest (1066) with the Tepanec War (1428–1430). Both changed ruling elites, but Norman England shows conquest by an external invader, while the Tepanec War shows a regional power shift that enabled Aztec expansion.
· Europe vs Africa and the Middle East: compare the Hundred Years’ War with the Great ‘Abbasid Civil War. Both weakened authority in the short term, but the Hundred Years’ War eventually strengthened French monarchy, while civil war in the Abbasid context is better used for fragmentation and legitimacy problems.
· Europe vs Middle East using Crusades: use Crusades only in one regional context. If using the Crusades for the Middle East, pair them with Norman conquest or Hundred Years’ War for Europe.
· Political vs social effects: the Wars of the Roses are strongest for political instability; the Crusades are stronger for religious and cultural change; the Norman conquest works for both political and social transformation.
· Short-term vs long-term: short-term effects are often violent disruption and regime change; long-term effects include state-building, boundary change, dynastic replacement, cultural exchange, or imperial fragmentation.

Exam-use guidance: turning notes into IB arguments

· For “Evaluate the effects”, rank effects by importance: political change is often easiest to prove, but social, economic, religious, and demographic impacts can make the answer more balanced.
· For “Compare and contrast”, use the same categories for each war: political, territorial, economic, social/religious, demographic, peacemaking.
· For “To what extent”, avoid one-sided answers. Example judgement: “The Norman conquest had its most immediate effect in dynastic replacement, but its greater long-term significance lay in transforming landholding and royal authority.”
· A strong paragraph should follow: claim → named war/date → specific effect → explanation of significance → link back to question.
· Use two-region examples deliberately. Do not write one detailed European essay and add a token non-European example at the end.

Judgement lines students can adapt

· Political effects were usually the most visible immediate consequence, because medieval war often decided rulers, succession, and control of territory.
· Economic and demographic effects were often uneven, falling hardest on civilians, conquered populations, and regions repeatedly campaigned through.
· Religious wars did not only produce religious effects: the Crusades also affected trade, settlement, diplomacy, and political authority.
· Civil wars often damaged legitimacy more than borders, as seen in the Toluid Civil War, Great ‘Abbasid Civil War, and Wars of the Roses.
· Long-term significance depends on whether war created a stable new order. The Norman conquest and Tepanec War produced new ruling structures; the Crusades show more limited success in peacemaking.

Exam traps or common mistakes

· Writing narrative instead of analysis: do not retell the war; explain effects and significance.
· Ignoring the syllabus categories: include political, economic, social, religious/cultural, and demographic where relevant.
· Forgetting “more than one region”: prepare at least one strong non-European example such as the Tepanec War, Toluid Civil War, or Great ‘Abbasid Civil War.
· Using the Crusades twice: in a two-region question, do not use the Crusades in Europe and Crusades in the Middle East as your two examples.
· Treating suggested examples as compulsory: they are suggested, but any replacement example must still fit 750–1500, the Paper 2 topic, and the effect being analysed.
· Confusing causes with effects: religious motives for the Crusades are causes; crusader states, cultural contact, displacement, and failed peacemaking are effects.