Medieval Europe · 1237–1242 (in Europe)

The Mongol Invasion of Europe: Why Did the Mongols Turn Back?

By the Aurelius editorial team · 3 min read · Updated 15 October 2026

Last time: in 1215 England's barons forced King John to seal Magna Carta. That same year, on the far side of the world, a Mongol army captured the city we call Beijing.

Under the year 1240, an English monk at St Albans entered news from the East that sounded like the end of the world. “An immense horde of that detestable race of Satan, the Tartars,” he wrote, had burst out of their mountains. In the spring of 1241 the horsemen were in Poland and Hungary.

From the steppe to Europe's edge

In 1206 a gathering of Mongol chiefs proclaimed Temüjin their ruler as Genghis Khan, a title whose meaning is debated, though it is often rendered “universal ruler”. In twenty years his armies overran much of northern China, Central Asia and eastern Persia. Their horse-archers could cover great distances, and their commanders coordinated columns by messenger.

After Genghis died in 1227 his empire kept growing under his sons and grandsons. In 1236 his grandson Batu and the veteran general Subutai led a large army, with many Turkic horsemen in its ranks, west to the Volga. Over the next four years they destroyed Rus' cities one after another, and Kyiv fell in December 1240.

Legnica and Mohi

In early 1241 the Mongols split. A smaller force rode through Poland and defeated Duke Henry II of Silesia at Legnica on 9 April; the duke was killed in the battle. Two days later the main army, under Batu and Subutai, destroyed the Hungarian army of King Béla IV at the river Sajó, at Mohi.

Hungary was then ravaged for a year. One modern estimate puts the loss at 15 to 25 per cent of the population, and archaeology shows that most villages on the Great Plain were destroyed, but no exact toll can be known. King Béla fled to the Adriatic coast. Western Europe, divided between a pope and an emperor in open conflict, offered no united response.

Why did they turn back?

In 1242 the Mongols withdrew from Central Europe. The traditional answer is the death of the Great Khan Ögedei in December 1241, which called Mongol princes home to choose a successor. Yet Batu himself did not go to the election: he stopped on the Volga, where his family founded the Golden Horde.

Other explanations are the weather, since a 2016 study of tree rings and written sources argued that a cold, wet early 1242 turned the Hungarian plain to marsh and spoiled the pasture, and the few stone fortresses that held out against the Mongols. Other scholars dispute the climate argument, and historians still disagree.

What Europe thought it saw

Europeans knew almost nothing about the invaders. They called them Tartars, from Tatars, but punned on Tartarus, the classical underworld, so that they could be “demons loosed from Tartarus”, as Matthew Paris wrote. His chronicle claims they drank blood and ate human flesh, which was fear speaking, not reporting.

The panic shaped diplomacy. In 1245 Pope Innocent IV sent the Franciscan John of Plano Carpini to the Great Khan's court in Mongolia, and in 1253 another friar, William of Rubruck, set out with the backing of King Louis IX. Their reports, and later Marco Polo's book, gave Europeans their first eyewitness accounts of the Mongol world.

The Mongol peace, and the plague

Once the conquests ended, the Mongol empires made the trade routes across Eurasia unusually safe. Merchants, missionaries and goods moved from China to the Black Sea. This is sometimes called the Pax Mongolica, the Mongol peace, and it had a darker side.

Batu's descendants ruled the Golden Horde from the Volga. In 1346, a Golden Horde army was besieging the Genoese trading port of Caffa in Crimea when plague struck it. Ships from Caffa and other Black Sea ports carried the disease west, and by October 1347 it had reached Messina in Sicily. The routes that brought silk and silver also brought the Black Death.

In their own words

“An immense horde of that detestable race of Satan, the Tartars, burst forth from their mountain-bound regions, and making their way through rocks apparently impenetrable, rushed forth, like demons loosed from Tartarus.”

Matthew Paris, Chronica Majora, year 1240, c. 1240–1259

Translation by J. A. Giles, Matthew Paris's English History from 1235 to 1273, vol. 1 (Bohn, 1852), p. 312. Matthew Paris was a monk of St Albans in England who never travelled east. His account mixes news from merchants and clergy with rumour and biblical prophecy, and shows how invaders were imagined before anyone had met them.

Why it happened

• Genghis Khan unified the steppe peoples in 1206 and gave the Mongol army a disciplined structure.
• Mongol horse-archers were far more mobile than the armies of Rus', Poland and Hungary, which had divided commands.
• Europe's rulers were preoccupied with their own conflicts and could not mount a joint defence.

What happened next

• Rus' principalities paid tribute to the Golden Horde for some two hundred years.
• Hungary rebuilt with stone castles, and western Europe made its first diplomatic contacts with the Mongols.
• Trade routes opened by the Mongol peace carried the plague to the Black Sea and then Europe. Read the story →

Why it still matters

After the invasion King Béla IV encouraged the building of stone castles and walled towns across Hungary. From about 1247 he fortified the hill above the Danube at Buda and settled there the townspeople of Pest, whose town the Mongols had burned. Budapest's Castle Hill, with its royal palace, grew from that refuge.

Connected stories

• Magna Carta, 1215: The Mongols took the Jin capital, today's Beijing, in 1215, the year of Magna Carta, yet Europe knew nothing of them for another two decades.
• The Black Death: The Golden Horde's siege of Caffa in 1346 was a stage in the plague's journey to Europe.
• The First Crusade: The crusaders went east to take a holy city; the Mongols arrived in Europe unannounced, and Latin Christendom had no army to meet them.

Sources

• Matthew Paris's English History from the Year 1235 to 1273, translated by J. A. Giles (Bohn, 1852–54)
• David Morgan, The Mongols (1986; 2nd ed. 2005)
• Reuven Amitai-Preiss and David O. Morgan (eds), The Mongol Empire and Its Legacy (1999)
• Christopher Dawson (ed.), The Mongol Mission (1955), including the accounts of John of Plano Carpini and William of Rubruck

Images are credited under each picture. Paintings and photographs come from public collections via Wikimedia Commons; scenes with no surviving image are marked as illustrations.