AQA · A-Level · History
Course version: 7042 · Version from Sept 2017
The origins of the Fourth Crusade; the papacy of Innocent III; the…
Full specification wording
1A The Age of the Crusades, c1071–1204 – The Third and Fourth Crusades, 1187–1204 (A-level only): The origins of the Fourth Crusade; the papacy of Innocent III; the weakness of the Byzantine Empire; the role of Venice
The Fourth Crusade (1202–1204) originated from Pope Innocent III’s 1198 encyclical Post miserabile, which sought to recapture Jerusalem.
Checked against the AQA 7042 specification (opens in a new tab) on .
- Point 4 of 6
- 4 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
The Fourth Crusade (1202–1204) originated from Pope Innocent III’s 1198 encyclical Post miserabile, which sought to recapture Jerusalem. The strategy to attack the Ayyubid power base in Egypt emerged later during crusade councils. The crusade was derailed by logistical failures and geopolitical opportunism. The role of Venice was pivotal; Doge Enrico Dandolo provided the fleet but, when the crusaders could not pay the 85,000 silver marks owed, diverted the army to attack Zara. Concurrently, the weakness of the Byzantine Empire, plagued by dynastic instability following the deposition of Isaac II, created a fatal vulnerability. Prince Alexios's promises of financial aid ultimately led to the catastrophic sack of Constantinople in 1204.
What earns the marks
- Analyse Pope Innocent III's motivations and methods in calling the crusade, including his use of plenary indulgences and direct papal taxation.
- Evaluate the terms of the Treaty of Venice (1201) and how the crusaders' overestimation of their numbers led to insurmountable debt.
- Assess the role of Doge Enrico Dandolo in redirecting the crusade to Zara and subsequently to Constantinople to serve Venetian commercial and political interests.
- Examine the internal dynastic conflicts of the Byzantine Empire, specifically the overthrow of Isaac II, which provided the pretext for crusader intervention.
Common mistakes and how to put them right
Stating that Innocent III planned the attack on Constantinople from the beginning.
Put it right: Innocent III explicitly forbade attacks on fellow Christians, though he lost control of the expedition.
Blaming the diversion solely on Venetian greed.
Put it right: Acknowledge the complex interplay of the crusaders' financial shortfall, the Treaty of Venice, and the opportunistic promises of Prince Alexios.
Assuming the Byzantine Empire was militarily strong but surprised.
Put it right: Highlight the chronic internal weaknesses, factionalism, and depleted treasury that left Constantinople vulnerable.
Claiming that Post miserabile explicitly targeted Egypt.
Put it right: The encyclical called for the recapture of Jerusalem, while the Egyptian strategy was formulated later by crusade leaders.
Exam tips
- Trace the chain of events chronologically to show how the initial papal origins were subverted by financial realities and Venetian influence.
- Use the figure of 85,000 silver marks to illustrate the scale of the crusaders' debt and explain why they became dependent on Venice.
- Discuss the Byzantine dynastic struggle as a pull factor that drew the crusaders to Constantinople, complementing the push factor of their debt.
Try the lesson
The start of the 1A The Age of the Crusades, c1071–1204 – The Third and Fourth Crusades, 1187–1204 (A-level only): The origins of the Fourth Crusade; the papacy of Innocent III; the weakness of the Byzantine Empire; the role of Venice lesson, made from checked teaching notes for this specification point.
Have a go first
What was Pope Innocent III's primary objective when he called for the Fourth Crusade in 1198?
Listen
The Fourth Crusade (1202–1204) originated from Pope Innocent III’s 1198 encyclical Post miserabile, which sought to recapture Jerusalem. The strategy to attack the Ayyubid power base in Egypt emerged later during crusade councils. The crusade was derailed by logistical failures and geopolitical opportunism. The role of Venice was pivotal; Doge Enrico Dandolo provided the fleet but, when the crusaders could not pay the 85,000 silver marks owed, diverted the army to attack Zara. Concurrently, the weakness of the Byzantine Empire, plagued by dynastic instability following the deposition of Isaac II, created a fatal vulnerability. Prince Alexios's promises of financial aid ultimately led to the catastrophic sack of Constantinople in 1204. A strong answer earns marks for these points. Analyse Pope Innocent III's motivations and methods in calling the crusade, including his use of plenary indulgences and direct papal taxation. Evaluate the terms of the Treaty of Venice (1201) and how the crusaders' overestimation of their numbers led to insurmountable debt. Assess the role of Doge Enrico Dandolo in redirecting the crusade to Zara and subsequently to Constantinople to serve Venetian commercial and political interests. Examine the internal dynastic conflicts of the Byzantine Empire, specifically the overthrow of Isaac II, which provided the pretext for crusader intervention. A common slip: Stating that Innocent III planned the attack on Constantinople from the beginning. Instead, Innocent III explicitly forbade attacks on fellow Christians, though he lost control of the expedition. Exam tip: Trace the chain of events chronologically to show how the initial papal origins were subverted by financial realities and Venetian influence.
Key words
Say what each word means before you turn the card.
Papal authority and ambition
Try answering aloud or in your head before turning the card.
Economic and logistical constraints
Try answering aloud or in your head before turning the card.
Dynastic instability
Try answering aloud or in your head before turning the card.
Commercial rivalry and opportunism
Try answering aloud or in your head before turning the card.
See every definition
- Papal authority and ambition
- Pope Innocent III's 1198 encyclical Post miserabile sought to recapture Jerusalem, and he used plenary indulgences and direct papal taxation.
- Economic and logistical constraints
- Logistical failures and the crusaders' overestimation of their numbers led to insurmountable debt, including 85,000 silver marks owed to Venice under the Treaty of Venice.
- Dynastic instability
- The Byzantine Empire was plagued by dynastic instability following the deposition of Isaac II, creating a fatal vulnerability and a pretext for crusader intervention.
- Commercial rivalry and opportunism
- Doge Enrico Dandolo redirected the crusade to Zara and subsequently to Constantinople to serve Venetian commercial and political interests, alongside the crusaders' financial shortfall and Prince Alexios's promises.
There is more to this lesson
The full lesson goes on to check your understanding and help you earn the marks. Create a free account to carry on, with your progress saved.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge
Test your understanding of 1A The Age of the Crusades, c1071–1204 – The Third and Fourth Crusades, 1187–1204 (A-level only): The origins of the Fourth Crusade; the papacy of Innocent III; the weakness of the Byzantine Empire; the role of Venice
Active recall beats re-reading. Take an instant quiz now to test what you’ve learned and lock it into long-term memory.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge