When the western half of the Roman Empire fell, the eastern half lasted almost another thousand years from its great capital, Constantinople.
🏰 Constantinople and Justinian
Emperor Constantine moved the capital east to Constantinople (today’s Istanbul) in 330 CE. Its position on the strait between Europe and Asia made it a great trading city and easy to defend with massive walls. Justinian I (reigned 527–565) won back parts of the old western empire, collected Roman law into the Justinian Code and rebuilt the church of Hagia Sophia (532–537). Byzantines spoke Greek and followed Orthodox Christianity.
Justinian’s reign: 565 − 527 = 38 years
Hagia Sophia built 532 → 537 = 5 years
Western Empire fell 476 → Constantinople fell 1453
1453 − 476 = 977 years
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🌐 Split and fall
In 1054 the Christian church split into the Roman Catholic church in the west and the Orthodox church in the east (the Great Schism). Byzantium faced attacks from Arabs, Bulgars, Turks and even Crusaders, who sacked Constantinople in 1204. In 1453 the Ottoman sultan Mehmed II captured the city with massive cannon, ending the Byzantine Empire. Byzantine scholars fleeing west carried Greek books to Italy.
Great Schism 1054 → fall 1453: 1453 − 1054 = 399 years
sack of Constantinople 1204 → 1453 = 249 years
Byzantine mosaics, domes and icons influenced church art in Russia and the Balkans for centuries, and Greek texts it preserved helped the Renaissance.
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Capital
The Byzantine capital was:
On the Bosporus.
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Justinian Code
The Justinian Code was a collection of:
Laws.
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Hagia Sophia
Hagia Sophia is famous for its:
Dome.
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1453
In 1453 Constantinople was captured by the:
Ottomans.
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Justinian reigned from 527 to 565.
How many years was his reign?
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years
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The Western Roman Empire fell in 476. The Byzantine capital fell in 1453.
How many years later did the eastern empire end?
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years
Subtract.
✍️ Type your answer · 7 of 7
The Great Schism of the church was in 1054.
How many years before the fall of Constantinople in 1453?
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years
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📝 Lesson quiz · 5 questions
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The Byzantine Empire was the:
Question 2 of 5
The Byzantines mainly spoke:
Question 3 of 5
The Great Schism divided Christianity into:
Question 4 of 5
Why was Constantinople easy to defend?
Question 5 of 5
Byzantine scholars helped the Renaissance by:
Lesson 2 · Medieval world
🕌 The Rise of Islam & the Golden Age
In the 600s a new religion spread from Arabia and within 100 years linked lands from Spain to India. Its cities became world centres of science, medicine and trade.
🌙 Origins and expansion
The Prophet Muhammad was born in Mecca about 570 CE. In 622 he and his followers travelled to Medina, the Hijra, which is year 1 of the Islamic calendar. After his death in 632, the caliphs led rapid expansion. The Umayyad caliphate (661–750) ruled from Damascus, and by 750 the Muslim world stretched from Spain to the Indus. The Islamic calendar is lunar, with about 354 days a year, 11 days shorter than a solar year of 365.
Hijra 622 → Muhammad died 632: 10 years
Umayyad: 750 − 661 = 89 years
lunar year 354 days vs solar 365: 365 − 354 = 11 days shorter
over 10 years: 10 · 11 = 110 days
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📚 Baghdad and the Golden Age
The Abbasid caliphs (750–1258) founded Baghdad in 762 and built the House of Wisdom, where scholars translated Greek, Persian and Indian works. Al-Khwarizmi (about 780–850) wrote the book from which the word algebra comes, and his name gave us algorithm. Ibn Sina (Avicenna) wrote the Canon of Medicine, used in Europe and Asia for centuries. Scholars improved the astrolabe, optics and paper-making. The Mongols captured Baghdad in 1258.
Abbasid caliphate: 1258 − 750 = 508 years
Baghdad founded 762 → sacked 1258: 1258 − 762 = 496 years
Arabic numerals (our digits 0–9) came to Europe through Muslim scholars, who learned them from India.
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Hijra
The Hijra was Muhammad’s journey from:
In 622.
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House of Wisdom
The House of Wisdom in Baghdad was a place for:
Learning.
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Algebra
Al-Khwarizmi’s work gave us the word:
Maths.
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Islamic calendar
The Islamic calendar is based on the:
Lunar.
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The lunar Islamic year has about 354 days and the solar year has 365.
How many days shorter is it over 10 years?
Enter an exact answer, without rounding.
days
Find the yearly gap first.
✍️ Type your answer · 6 of 7
The Abbasid caliphate lasted from 750 to 1258.
How many years was that?
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years
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Baghdad was founded in 762 and captured by the Mongols in 1258.
How many years was that?
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years
Subtract.
📝 Lesson quiz · 5 questions
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Question 1 of 5
The first year of the Islamic calendar is the year of the:
Question 2 of 5
Muslim scholars helped Europe by:
Question 3 of 5
The Canon of Medicine was written by:
Question 4 of 5
The Abbasid capital was:
Question 5 of 5
By 750 the Muslim world stretched from:
Lesson 3 · Medieval world
🏰 Medieval Europe
After Rome, Europe was a patchwork of kingdoms bound by land, loyalty and the Church. Disease, war and new ideas slowly changed that world.
👑 Feudalism and the Church
In feudalism the king gave land (fiefs) to lords in return for military service; lords gave land to knights; and peasants (serfs) farmed the land and owed the lord labour and a share of the crops. The Church was powerful and wealthy and ran schools and hospitals. Charlemagne, king of the Franks, was crowned emperor in 800. William of Normandy won the Battle of Hastings in 1066. In 1215 English barons forced King John to sign the Magna Carta, which said that even the king must obey the law.
Charlemagne crowned 800 → Hastings 1066: 1066 − 800 = 266 years
Hastings 1066 → Magna Carta 1215: 1215 − 1066 = 149 years
a serf owes the lord 3 days of labour in a 6-day working week:
3 / 6 = 1/2 of the working week
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Land and loyalty flowed down; labour and food flowed up.
☠️ The Black Death and war
The Black Death (plague) reached Europe in 1347 and raged until about 1351, killing roughly one third or more of the people. Labour became scarce, so surviving peasants could demand better pay and freedom, weakening feudalism. Meanwhile England and France fought the Hundred Years’ War (1337–1453). The Crusades, begun in 1095, were wars to control Jerusalem and the Holy Land, and they increased contact between Europe and the Islamic world.
Europe about 75 million people; one third died:
75 / 3 = 25 million deaths
Hundred Years’ War: 1453 − 1337 = 116 years
Black Death 1347 → 1351 = 4 years
Fleas on rats spread the plague (the bacterium Yersinia pestis), and trade routes carried it from Asia to Europe.
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Feudalism
In feudalism, knights received land in return for:
Fight for the lord.
✏️ Quick check · 2 of 7
Magna Carta
The Magna Carta of 1215 established that:
No one above law.
✏️ Quick check · 3 of 7
Black Death
The Black Death spread along:
Through trade.
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Peasants after plague
After the plague, surviving peasants could often:
Fewer workers.
✍️ Type your answer · 5 of 7
Hastings was in 1066 and the Magna Carta was signed in 1215.
How many years between them?
Enter an exact answer, without rounding.
years
Subtract.
✍️ Type your answer · 6 of 7
Europe had about 75 million people and one third died of plague.
How many millions died?
Enter an exact answer, without rounding.
million
Divide by 3.
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The Hundred Years’ War began in 1337 and ended in 1453.
How many years is that?
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years
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📝 Lesson quiz · 5 questions
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Question 1 of 5
A serf was a:
Question 2 of 5
Charlemagne was crowned emperor in:
Question 3 of 5
The Hundred Years’ War was between:
Question 4 of 5
The Crusades aimed to:
Question 5 of 5
The Church in the Middle Ages:
Lesson 4 · Medieval world
🐎 The Mongol Empire & the Silk Road
In just a few decades, horse-riding herders from the grasslands of Mongolia built the largest connected land empire in history.
🏹 Genghis Khan and conquest
Temujin united the Mongol tribes and in 1206 took the title Genghis Khan (“universal ruler”). Mongol armies were made of fast horse archers who used speed, discipline and tricks to defeat larger forces. Under Genghis and his successors the empire conquered Central Asia, China, Persia and Russia; in 1258 Baghdad fell. At its peak the empire covered about 24 million km². Genghis died in 1227, and the empire later split into four khanates.
Genghis Khan ruled 1206 → 1227: 1227 − 1206 = 21 years
Baghdad 1258 − 1206 = 52 years after the first khan
horse archer rides 80 km a day: 400 km / 80 = 5 days
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🧭 The Pax Mongolica
Once conquered, the Mongols protected trade routes and used relay stations (the yam) so messengers could cover huge distances. This Pax Mongolica made the Silk Road safer than ever. Kublai Khan founded the Yuan dynasty in China in 1271, and the Venetian merchant Marco Polo travelled to his court, returning in 1295. Goods, ideas and also disease moved along these routes; the plague that reached Europe in 1347 probably travelled along them.
Kublai Khan’s Yuan dynasty: 1271 → 1368 = 97 years
Marco Polo travelled 1271 → 1295 = 24 years
relay stations 40 km apart: 400 km route needs 400/40 = 10 stages
Tolerance and trade: the Mongols allowed many religions, and moved craftsmen, scholars and technologies such as paper, gunpowder and the compass across Eurasia.
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Genghis Khan
Genghis Khan first became leader of:
Mongols.
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Horse archers
Mongol armies were successful mainly because of:
Fast riders.
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Pax Mongolica
The Pax Mongolica was a period when:
Peace under Mongols.
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Marco Polo
Marco Polo was a:
Italian trader.
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Genghis Khan ruled from 1206 to 1227.
How many years was that?
Enter an exact answer, without rounding.
years
Subtract.
✍️ Type your answer · 6 of 7
The Yuan dynasty lasted from 1271 to 1368.
How many years is that?
Enter an exact answer, without rounding.
years
Subtract.
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A messenger route is 400 km and relay stations are 40 km apart.
How many stages are there?
Enter an exact answer, without rounding.
Divide.
📝 Lesson quiz · 5 questions
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Question 1 of 5
Kublai Khan founded the:
Question 2 of 5
The Mongol empire at its peak was:
Question 3 of 5
The yam was the Mongol:
Question 4 of 5
Mongol rule helped spread:
Question 5 of 5
Baghdad fell to the Mongols in:
Lesson 5 · Medieval world
👑 Medieval Africa & Asia
Between about 500 and 1500 CE, wealthy kingdoms and empires flourished in West Africa, Southern Africa, China, Japan and Southeast Asia.
🌍 Mali, Songhai and Zimbabwe
West Africa’s wealth came from gold and salt carried across the Sahara. The Mali Empire was founded by Sundiata Keita about 1235. Its ruler Mansa Musa made a lavish pilgrimage to Mecca in 1324, giving away so much gold that its price fell in Cairo. Timbuktu grew into a centre of scholarship with libraries and a university. Songhai later became the largest empire in West Africa. In southern Africa, Great Zimbabwe (11th–15th centuries) built huge stone walls and traded gold to the Indian Ocean coast.
Mali founded about 1235 → Mansa Musa’s pilgrimage 1324
1324 − 1235 = 89 years
Sahara caravan: 1000 km at 25 km a day
1000 / 25 = 40 days
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Trade routes across the Sahara, the Indian Ocean and the Silk Road made medieval Africa and Asia wealthy and connected.
🏯 China, Japan and Angkor
The Tang (618–907) and Song (960–1279) dynasties were golden ages in China: woodblock printing, the magnetic compass, gunpowder and paper money. In Japan, power shifted from the emperor to military leaders: the first shogun took charge in 1185 and samurai warriors served the daimyo (lords). The Khmer Empire in Cambodia built Angkor Wat in the early 1100s, the largest religious monument in the world.
Song dynasty: 1279 − 960 = 319 years
Tang dynasty: 907 − 618 = 289 years
first shogun 1185 → Mongols complete conquest of Song 1279: 94 years
Four great Chinese inventions: paper, printing, gunpowder and the compass. All spread west along trade routes.
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Mansa Musa
Mansa Musa is remembered for:
Gold.
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Timbuktu
Timbuktu was important as a centre of:
Books and trade.
✏️ Quick check · 3 of 7
Samurai
Samurai served:
Warrior class.
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Song inventions
Which came from medieval China?
Four great inventions.
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Mali was founded about 1235. Mansa Musa made his pilgrimage in 1324.
How many years later was that?
Enter an exact answer, without rounding.
years
Subtract.
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The Song dynasty lasted from 960 to 1279.
How many years?
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years
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The Tang dynasty lasted from 618 to 907.
How many years?
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years
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📝 Lesson quiz · 5 questions
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Question 1 of 5
West African empires grew rich from trading:
Question 2 of 5
Angkor Wat was built by the:
Question 3 of 5
A shogun was a:
Question 4 of 5
Great Zimbabwe is known for its:
Question 5 of 5
Paper money was first used in:
Lesson 6 · Medieval world
🗿 The Aztec & Inca Empires
In the Americas, two great empires built cities and road networks without wheeled carts or iron tools, until Spanish conquerors arrived in the early 1500s.
🌊 The Aztecs
The Mexica (Aztecs) founded Tenochtitlan on an island in Lake Texcoco in 1325. They built causeways, canals and chinampas (floating gardens) that gave several harvests a year. By 1500 Tenochtitlan held perhaps 200 000 people, bigger than most European cities. Subject peoples paid tribute to the Aztec rulers. In 1521 Spanish forces under Hernán Cortés, aided by Aztec enemies and by smallpox, took the city.
Tenochtitlan 1325 → conquest 1521: 1521 − 1325 = 196 years
200 000 people; 1 in 4 farm the chinampas:
200 000 / 4 = 50 000 farmers
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🏔️ The Incas
The Inca Empire (about 1438–1533) stretched about 4000 km along the Andes with its capital at Cusco and perhaps 10 million people. A road network of about 40 000 km, with runners (chasqui) carrying messages, held it together. Farmers cut terraces into steep slopes. Without writing, officials kept records with khipu, knotted cords that stored numbers. The Inca built Machu Picchu about 1450. In 1533 Francisco Pizarro captured the Inca ruler Atahualpa and the empire fell.
Inca Empire 1438 → 1533: 1533 − 1438 = 95 years
roads 40 000 km, runner covers 20 km per stage; relay needs 40 000/20 = 2000 stages
khipu: 3 knots in one position, 2 in another: 32 (tens and units)
The Columbian Exchange began with these conquests: diseases such as smallpox devastated Indigenous populations who had no immunity.
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Chinampas
Aztec chinampas were:
Floating gardens.
✏️ Quick check · 2 of 7
Khipu
The Incas recorded numbers using:
Strings.
✏️ Quick check · 3 of 7
Chasqui
The chasqui were:
Runners.
✏️ Quick check · 4 of 7
Conquest
The Spanish conquest was helped by:
Germs.
✍️ Type your answer · 5 of 7
Tenochtitlan was founded in 1325 and conquered in 1521.
How many years was that?
Enter an exact answer, without rounding.
years
Subtract.
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The Inca Empire existed from about 1438 to 1533.
About how many years?
Enter an exact answer, without rounding.
years
Subtract.
✍️ Type your answer · 7 of 7
A city of 200 000 people has one quarter working as farmers.
How many farmers is that?
Enter an exact answer, without rounding.
people
Divide.
📝 Lesson quiz · 5 questions
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Question 1 of 5
The Aztec capital was:
Question 2 of 5
The Inca capital was:
Question 3 of 5
Cortés conquered the:
Question 4 of 5
Pizarro conquered the:
Question 5 of 5
Inca terraces were used to:
Final Challenge
🏆 12-Question Challenge Quiz
Questions from every topic in this course. Pick an answer for each one, then hit Check My Answers.
0 / 12
💪 Keep practicing — go back through the lessons and retake the quiz!
Q1 · The Byzantine Empire
Which emperor rebuilt Hagia Sophia and compiled Roman law?
Q2 · The Byzantine Empire
Byzantine scholars helped the Renaissance by:
Q3 · The Rise of Islam & the Golden Age
Our word “algorithm” comes from the name of:
Q4 · The Rise of Islam & the Golden Age
By 750 the Muslim world stretched from:
Q5 · Medieval Europe
Which event weakened feudalism by making labour scarce?
Q6 · Medieval Europe
The Church in the Middle Ages:
Q7 · The Mongol Empire & the Silk Road
The plague that reached Europe in 1347 probably travelled along:
Q8 · The Mongol Empire & the Silk Road
Baghdad fell to the Mongols in:
Q9 · Medieval Africa & Asia
Which empire’s ruler made the pilgrimage to Mecca in 1324?