CBSE Class 10 · The Making of a Global World

Conquest, Disease and Trade Class 10: How the World Shrank

Updated 14 October 2026 · Fact-checked

In the sixteenth century European sailors found a sea route to Asia and crossed to America, so the world 'shrank'. Silver from Peru and Mexico enriched Europe. Spanish and Portuguese conquest succeeded mainly because smallpox, to which isolated Americans had no immunity, killed whole communities. Slave plantations and China's withdrawal moved the centre of world trade to Europe.

Notice that germs sailing west, not just guns, beat the Americans, while silver sailing east made Europe richer.

Illustration drawn for QuestionBuddy.

Understand Conquest, Disease and Trade

The world 'shrank' in the sixteenth century. Two voyages changed everything: European sailors found a sea route to Asia, and they also crossed the western ocean to America. Distant regions were now joined by regular sea travel.

India's place before the Europeans. For centuries the Indian Ocean had a bustling trade in goods, people, knowledge and customs. The Indian subcontinent was central to these flows and a crucial point in their networks. When Europeans entered, they expanded some of these flows and redirected others towards Europe.

America enters the world economy. Before its 'discovery', America had been cut off from regular contact with the rest of the world for millions of years. From the sixteenth century its vast lands, plentiful crops and minerals began to transform trade and lives everywhere.

Silver: precious metals, especially silver from mines in present-day Peru and Mexico, added to Europe's wealth and paid for its trade with Asia.
El Dorado: in seventeenth-century Europe, stories spread about South America's legendary riches, and many expeditions went looking for El Dorado, the fabled city of gold.

Conquest and germs. By the mid-sixteenth century the Portuguese and Spanish conquest and colonisation of America was decisively under way. Their victory was not only about better guns. The Spanish conquerors' most powerful weapon was not a military one at all: it was the germs, such as smallpox, carried on their bodies.

America's original inhabitants had lived in isolation for so long that they had no immunity to these European diseases.
Smallpox was the deadliest. Once it arrived it spread deep into the continent, even ahead of the Europeans, and killed or wiped out whole communities. This cleared the way for conquest.
Guns could be bought or captured and turned against the invaders, but a disease could not be turned back on conquerors who were mostly immune to it.

Box 1, 'Biological' warfare? The chapter quotes John Winthorp, first governor of the Massachusetts Bay colony in New England. In May 1634 he wrote that smallpox was a sign of God's blessing for the colonists, because the natives were nearly all dead of it and so the colonists' claim to the land was 'cleared'. The quotation is from Alfred Crosby's book *Ecological Imperialism*. It shows how the colonisers saw the deaths of the native people as a gain.

Why Europeans went to America. Until the nineteenth century, poverty and hunger were common in Europe. Cities were crowded, deadly diseases were widespread, religious conflicts were common and religious dissenters (people who refuse to accept established beliefs and practices) were persecuted. So thousands fled Europe for America. By the eighteenth century, plantations there, worked by slaves captured in Africa, grew cotton and sugar for European markets. Fig. 5 (Illustrated London News, 1851) shows slaves lined up for auction in New Orleans, dressed in their best clothes to attract buyers.

The centre of world trade moves west. Until well into the eighteenth century, China and India were among the world's richest countries and leaders in Asian trade. But from the fifteenth century China is said to have limited its overseas contacts and withdrawn into isolation. China's smaller role and the rising importance of the Americas gradually shifted the centre of world trade westwards, and Europe became the centre of world trade.

Exam scope. This section ends the board-assessed part of the chapter (Sections 1 to 1.3). The nineteenth century, indentured labour, the Depression and Bretton Woods are for the internal project only.

Conquest, Disease and Trade: key facts

Why the world 'shrank': 16th century: sea route to Asia found + western ocean crossed to America; Answer for 'explain what we mean when we say the world shrank'.
India's role: Indian Ocean trade in goods, people, knowledge and customs; the Indian subcontinent central and a crucial point in the networks; Europeans expanded or redirected these flows towards Europe.
Silver and El Dorado: Silver from mines in present-day Peru and Mexico
Effect enriched Europe, financed Asian trade
17th century legends of El Dorado, the fabled city of gold; Not a real city.
Smallpox as a weapon: Long isolation, so no immunity; smallpox spread ahead of Europeans and decimated communities; conquest under way by the mid-16th century; Guns could be captured; germs could not be turned back.
Push factors from Europe: Poverty, hunger, crowded cities, deadly diseases, religious conflicts, persecution of dissenters; Why thousands fled to America.
Plantations: 18th century: African slaves grew cotton and sugar for European markets; Fig. 5: slave auction, New Orleans, 1851.
Shift of trade centre: China retreats from the 15th century + Americas rise = Europe becomes the centre of world trade; China and India were among the richest until well into the 18th century.

Silver	from mines in present-day Peru and Mexico
Effect	enriched Europe, financed Asian trade
17th century	legends of El Dorado, the fabled city of gold

How to answer Conquest, Disease and Trade questions

This section is set as MCQs, 2-mark explanations (smallpox, Indian subcontinent, why Europeans fled) and source passages from Box 1. Keep each point tied to a cause and its effect.

1Spot the cause-effect chain the question wants: isolation leads to no immunity, which leads to deaths and then conquest.
2For smallpox, always contrast germs with guns: guns could be captured, diseases could not be turned back.
3For 'why Europeans fled', list push factors from Europe, not attractions of America.
4For India's role, say 'central to Indian Ocean flows' and add that Europeans redirected them.
5For the shift of the trade centre, give two causes: China's withdrawal and the rise of the Americas.
6In source questions on Box 1, separate what Winthorp claims from what it shows about colonisers' attitudes.

Conquest, Disease and Trade in real life

The idea, met in an everyday situation. Answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Isolation and lack of immunity

Suppose a group of students from a remote hill hostel, who have never met outsiders, go on a city trip. Visitors carry a common infection that city children shake off easily, but many of the hostel students fall seriously ill.

Explain why the hostel students suffered more, and link the idea to the conquest of America.

Try it first, then show the solutionSolution

Identify the cause: the hostel students had no earlier exposure, so no immunity.
Link to America: long isolation meant the native people had no immunity to European diseases.
Add the outcome: smallpox killed whole communities and prepared the way for conquest.

Answer: In this imagined case, the city children had met the infection before and resisted it, while the isolated students had no immunity. America's original inhabitants were in the same position on a far larger scale: cut off for millions of years, they had no immunity to smallpox brought by the Spanish. The disease spread ahead of the conquerors and wiped out communities, making conquest easier.

Memory hook: No contact, no immunity; no immunity, no defence.

Tricks to remember Conquest, Disease and Trade

Short memory aids. Say each one aloud once, then use it on a question the same day.

S-S-S of the 1500s
Sea route, Silver, Smallpox: three things that shrank the sixteenth-century world.
Use it when: Quick plan for 'how the world shrank' answers.
Guns turn, germs don't
A gun can be captured and fired back; a germ cannot.
Use it when: Justifying 'smallpox was the most powerful weapon'.
PHD-RP push
Poverty, Hunger, Diseases, Religious conflict, Persecution: why Europeans fled.
Use it when: 2-mark migration questions.

Conquest, Disease and Trade: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: The disease that cleared the way · 1 mark · MCQBoard level

The germs of which disease paved the way for the Spanish conquest of America in the sixteenth century?
(a) Plague
(b) Cholera
(c) Smallpox
(d) Influenza

Try it first, then show the solutionSolution

The text names smallpox as the deadliest of the European germs (1 mark).

Answer: (c) Smallpox

Example 2: Germs rather than guns (2 marks) · 2 marks · Very short answerBoard level

Explain two ways in which germs, rather than guns, decided the Spanish conquest of America. (2 marks)

Try it first, then show the solutionSolution

The Spanish carried germs such as smallpox; America's people, isolated for millions of years, had no immunity and whole communities died, even before Europeans reached them (1 mark).
Guns could be bought or captured and used against invaders, but diseases could not, as the conquerors were mostly immune (1 mark).

Answer: The Spanish carried smallpox germs, and America's isolated people had no immunity, so the disease spread ahead of the conquerors and wiped out whole communities. Unlike guns, which could be captured and turned on the invaders, germs could not be used against conquerors who were mostly immune.

Example 3: Why Europe became the centre of trade (3 marks) · 3 marks · Short answerHarder board level

Explain how Europe emerged as the centre of world trade after the sixteenth century, although China and India were among the richest countries until well into the eighteenth century. (3 marks)

Try it first, then show the solutionSolution

From the fifteenth century China is said to have restricted overseas contacts and retreated into isolation (1 mark).
The Americas grew in importance: silver from Peru and Mexico enriched Europe and paid for its Asian trade, and slave plantations grew cotton and sugar for Europe (1 mark).
China's reduced role and the rise of the Americas moved the centre of world trade westwards to Europe (1 mark).

Answer: From the fifteenth century China is said to have withdrawn from overseas contact. Meanwhile the Americas grew in importance: silver from Peru and Mexico enriched Europe and financed its trade with Asia, and slave plantations grew cotton and sugar for European markets. China's smaller role and the rise of the Americas shifted the centre of world trade west to Europe.

Example 4: Assertion-reason: India and the Indian Ocean · 1 mark · Assertion-reasonHarder board level

Assertion (A): Before the Europeans arrived, the Indian subcontinent was central to trade across the Indian Ocean.
Reason (R): The entry of Europeans in the sixteenth century ended all trade flows across the Indian Ocean.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.

Try it first, then show the solutionSolution

A is true. R is false: Europeans expanded or redirected some flows towards Europe; they did not end them (1 mark).

Answer: (c) A is true, but R is false.

Example 5: Source: Box 1, 'Biological' warfare? · 4 marks · Source-basedHOTS / competency

Read the source and answer the questions.

Source (NCERT Box 1, in summary): John Winthorp, the first governor of the Massachusetts Bay colony in New England, wrote in May 1634 that smallpox was a sign of God's blessing for the colonists. The natives, he wrote, were nearly all dead of smallpox, and so the Lord had cleared the colonists' title to what they possessed. The extract is quoted from Alfred Crosby's book Ecological Imperialism.

(i) Who was John Winthorp? (1)
(ii) What, according to Winthorp, had the deaths from smallpox done for the colonists? (1)
(iii) Why do you think the box is titled 'Biological' warfare, with the word in quotation marks? (2)

Try it first, then show the solutionSolution

(i) The first governor of the Massachusetts Bay colony in New England (1 mark).
(ii) It had 'cleared' their title, or claim, to the land they possessed (1 mark).
(iii) Disease worked like a weapon: it killed the native people and won land for the colonists without battle (1 mark).
(iii) The quotation marks show it was not deliberate warfare in the usual sense; the germs were carried unknowingly, yet colonists welcomed the result as a blessing (1 mark).

Answer: (i) He was the first governor of the Massachusetts Bay colony in New England. (ii) He believed the deaths had cleared the colonists' title to the land. (iii) Smallpox acted like a weapon, killing the native people and handing land to the colonists without fighting. The quotation marks suggest this was not planned warfare in the normal sense, since germs were carried unknowingly, but the colonists treated the result as a blessing and a gain.

Example 6: Conquest, disease and trade (5 marks) · 5 marks · Long answerHarder board level

'The pre-modern world shrank greatly in the sixteenth century.' Examine how conquest, disease and trade together transformed the world in this period. (5 marks)

Try it first, then show the solutionSolution

European sailors found a sea route to Asia and crossed the western ocean to America; they expanded or redirected Indian Ocean flows towards Europe (1 mark).
America, isolated for millions of years, began to transform trade with its lands, crops and minerals; silver from Peru and Mexico enriched Europe and financed Asian trade (1 mark).
Portuguese and Spanish conquest was under way by the mid-sixteenth century, helped above all by smallpox, to which native people had no immunity (1 mark).
Europeans escaping poverty, disease and persecution settled in America; by the eighteenth century African slaves worked cotton and sugar plantations for Europe (1 mark).
With China withdrawing and the Americas rising, the centre of world trade moved west to Europe (1 mark).

Answer: In the sixteenth century Europeans found a sea route to Asia and crossed to America, so distant regions were joined. They entered the Indian Ocean trade, where India had been central, and redirected some flows to Europe. America, isolated for millions of years, now changed world trade: silver from Peru and Mexico enriched Europe and paid for its Asian trade. Spanish and Portuguese conquest succeeded largely because smallpox, against which native people had no immunity, wiped out communities. Europeans fleeing poverty and persecution settled there, and African slaves grew cotton and sugar for Europe. As China withdrew and the Americas rose, Europe became the centre of world trade.

Where students lose marks in Conquest, Disease and Trade

The slips examiners see most often, and what to write instead.

Mistake: Saying the Spanish spread smallpox on purpose
The phrase 'biological warfare' is taken literally.
Wrong working
The Spanish deliberately infected the natives with smallpox.
Right working
The conquerors carried the germs on their person; native people lacked immunity.
Do this: Write 'carried', not 'used deliberately'.
Usually costs: 1 mark.
Mistake: Leaving out immunity
Students say 'smallpox killed many' without the reason.
Wrong working
Smallpox was a deadly disease, so many died.
Right working
Long isolation meant no immunity, so smallpox killed whole communities.
Do this: Always give isolation, immunity, deaths, conquest.
Usually costs: 1 mark in 2-mark answers.
Mistake: Writing attractions of America for 'why Europeans fled'
The question asks about push factors.
Wrong working
They went because America had gold.
Right working
They fled poverty, hunger, disease and religious persecution in Europe.
Do this: Read 'fled' as 'what pushed them'.
Usually costs: 1-2 marks.
Mistake: Saying Europeans ended Indian Ocean trade
Overstating the European impact.
Wrong working
Europeans destroyed Indian Ocean trade.
Right working
They helped expand or redirect some flows towards Europe.
Do this: Use the verbs 'expand' and 'redirect'.
Usually costs: 1 mark in assertion-reason.

Exam tips

Learn the sequence isolation, no immunity, smallpox, conquest: it earns both marks in 2-mark answers.
Use Box 1 and Figs. 4-5 captions as ready material for source questions.
For 'Europe became the centre of world trade', always give two causes: China's withdrawal and the Americas' rise.
This is the last board-assessed section of the chapter; do not write about Corn Laws or indentured labour in board answers.

Practice questions on Conquest, Disease and Trade

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 1 mark · MCQBoard level
In seventeenth-century Europe, El Dorado was famous as:
(a) a Spanish port
(b) the fabled city of gold in South America
(c) a silver mine in Mexico
(d) a slave market in New Orleans
Hint
Legends of South America's wealth.
Answer
(b) the fabled city of gold in South America
Q2 · 2 marks · Very short answerBoard level
Why did thousands of people flee Europe for America until the nineteenth century? Give two reasons. (2 marks)
Hint
Conditions in Europe, not attractions in America.
Answer
Poverty and hunger were common, cities were crowded and deadly diseases widespread. Religious conflicts were common and religious dissenters were persecuted, so many left to escape.
Q3 · 2 marks · Very short answerHarder board level
How did silver from America change Europe's position in world trade? (2 marks)
Hint
Peru and Mexico; what did Europe pay for?
Answer
Silver from mines in present-day Peru and Mexico increased Europe's wealth and paid for its trade with Asia. This helped Europe expand its trade and, with China's withdrawal, become the centre of world trade.
Q4 · 3 marks · Short answerHOTS / competency
A classmate says, 'The Spanish won America because their guns were better.' Evaluate this view using the NCERT text. (3 marks)
Hint
Accept part of it, then bring in germs and immunity.
Answer
Only partly true. The text says conquest was not just a result of superior firepower. The decisive factor was germs like smallpox: native Americans had no immunity because of long isolation, so the disease spread ahead of the Spanish and wiped out communities. Also, guns could be captured and turned against invaders, but germs could not.
Q5 · 3 marks · Short answerHarder board level
Explain the link between European demand and African slavery in the Americas by the eighteenth century. (3 marks)
Hint
What did plantations grow, for whom, and with whose labour?
Answer
By the eighteenth century, plantations in America grew cotton and sugar to sell in European markets. They needed large amounts of labour, which was supplied by slaves captured in Africa. So European demand for these goods drove a trade in which Africans were forced to work on American plantations; Fig. 5 shows slaves for sale in New Orleans in 1851.
Q6 · 3 marks · Short answerHOTS / competency
Suppose a textbook timeline has only one line for the sixteenth century: 'Europeans discover America.' Rewrite it as three lines that show why the period matters for global history. (3 marks)
Hint
Routes, wealth, conquest.
Answer
1. European sailors find a sea route to Asia and cross to America, and the world shrinks. 2. Silver from Peru and Mexico enriches Europe and finances its Asian trade. 3. Spanish and Portuguese conquest, helped by smallpox, is decisively under way by the mid-sixteenth century.
Q7 · 1 mark · MCQBoard level
Who is a dissenter?
(a) A trader on the silk routes
(b) One who refuses to accept established beliefs and practices
(c) A slave on an American plantation
(d) A governor of a colony
Hint
See 'New words' in the chapter.
Answer
(b) One who refuses to accept established beliefs and practices

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.From where did silver reach Europe?Show answer
Mines in present-day Peru and Mexico.
2.By when was Spanish and Portuguese conquest of America decisively under way?Show answer
By the mid-sixteenth century.
3.Who wrote Ecological Imperialism?Show answer
Alfred Crosby.
4.What did American plantations grow by the eighteenth century?Show answer
Cotton and sugar, for European markets.
5.From when did China restrict overseas contacts?Show answer
From the fifteenth century.
6.What does Fig. 5 show?Show answer
Slaves for sale at an auction in New Orleans, 1851.

Conquest, Disease and Trade: frequently asked questions

How did smallpox help the Spanish conquer America?

Native Americans, isolated for millions of years, had no immunity. Smallpox spread ahead of the conquerors and wiped out whole communities, paving the way for conquest.

What does 'the world shrank in the sixteenth century' mean?

European sailors found a sea route to Asia and crossed to America, so distant parts of the world were brought into regular contact.

Why did Europe become the centre of world trade?

China withdrew into isolation from the fifteenth century, while the Americas rose in importance through silver and plantation crops, so the centre of trade moved west to Europe.

What was El Dorado?

A fabled city of gold in South America; many seventeenth-century European expeditions went in search of it.