The Mongol Horde enjoyed a fearsome reputation as a largely undefeated fighting force. They conquered China, terrorized Eastern Europe, sacked Baghdad, and attacked the Mamluks in Egypt. Their military prowess won them the largest contiguous land empire in history.

Mongol Conquest of China

The Great Wall of China was built to keep northern forces from raiding China, but in the 13th century C.E., the wall provided little help against the armies of Mongol invaders. Under the leadership of the infamous Genghis Khan and, later, his grandson, Kublai Khan, Mongol nomads overran the Chinese armies and ushered in the Yuan Dynasty of China. Over the course of its existence, the empire would become the largest contiguous land empire in history.

The Mongol invasion of China started in 1211 when Genghis Khan’s forces took on the northern Chinese Jin Empire. Mongols took advantage of the fractured state of China, which was then divided into the Song Empire in the south and the Jin Empire in the north. Genghis Khan allied his forces with defectors from the Jin state in order to overtake their army. The Mongols learned siege warfare techniques from the Chinese, which helped them extend their military outfitting beyond their significant cavalry forces. The Jin state was absorbed into the Mongol Empire under Ogodei Khan in 1234.

After a period of peace between Mongols in the northern region of China and the southern Song Empire, the grandson of Genghis Khan, Kublai Khan, began a second invasion of the Chinese region. Mongol forces besieged the Song’s important fortress city of Xianyang for five years before conquering it and moving on. The last Song emperor was a young boy. He, his mother, and the imperial court fled the Mongol forces. In 1279, with Mongol invaders closing in, a loyal minister carrying the eight-year-old emperor jumped into the ocean, and both drowned. The boy’s demise marked the complete takeover of China by Mongol rulers. Kublai Khan went on to become the first emperor of the Yuan Dynasty, which lasted until 1368. Under the rule of Kublai Khan, the Mongol Empire became the largest contiguous empire ever seen.

Mongols Go West

Conquering China was a major victory, but it was just the beginning for the Mongols. In the 1230s, they began to head west, eyeing territory in Eastern Europe. Batu, another grandson of Genghis Khan, expanded Mongol rule to modern-day western Russia, Ukraine, and all the way up to the Carpathian Mountains. In the east, Batu extended Mongol territory to Siberia. The Mongol army burned and sacked the city of Kiev in Ukraine in 1240. Forces marched onward toward Hungary and Poland, defeating the Hungarian and Polish armies and causing the Hungarian king to flee.

However, by 1242, despite weak military resistance from Hungary, the Mongol forces turned back without overtaking Hungary. The reasons for this retreat are largely unknown, but scholars have previously suggested that the death of the Great Khan Ogodei may have compelled the army to return to Mongolia in order to decide who would succeed their ruler. However, some researchers have proposed a new theory based on a study of climate data for that region. While unusual cold and snow may have helped the Mongols cross the frozen Danube River in the winter, the spring weather was not so forgiving. That particular spring brought unusually wet and marshy conditions, which may have wreaked havoc with the horses of the Mongol forces. Wet and muddy conditions would have interfered with the cavalry’s mobility, and would have limited where their horses could graze due to flooded pastures. If these researchers are correct, it may have been the wellbeing of Mongols’ horses, and not their emperor's death, that compelled them to give up their campaign in Eastern Europe.

This western part of the Mongol Empire established by Batu, was known as the Golden Horde. It is unclear why this part of the empire received this name, but a theory is that it was named after the yellow tents employed by the Mongol army. Batu settled his capital near the Volga River at Sarai Batu. He and his descendants ruled over the Russian and Eastern European territory until eventually succumbing to dynastic squabbles, which left them vulnerable to attacks from other regional powers. The remnants of the Golden Horde in Crimea were defeated by the Ottomans in 1502.

The Sack of Baghdad

Mongol forces sacked Baghdad, the jewel of the Abbasid Caliphate, in 1258. Under the direction of Hulegu Khan, another Genghis Khan's grandsons, the Mongols directed themselves to subduing Muslim forces in modern-day Iran, Iraq, and Syria. Hulegu came to control all of Iran and founded the Il-khan Dynasty. (Il-khan means subordinate khan in Persian.)

The sack of Baghdad began in 1258 when Hulegu sent a letter to the caliph of Baghdad demanding control of the city and threatening to destroy everything should he not receive it. The caliph, Mustasim, did not take Hulegu’s threat seriously and did little to properly defend the city. There was also some internal strife between the caliph and his subjects, which prevented any appropriate response to the Mongol threat.

The Mongols pillaged and sacked Baghdad on an disasterous scale. They killed hundreds of thousands of Baghdad’s residents and razed art and architecture to the ground. The Mongols threw all the books from the libraries of Baghdad into the Tigris River. Mustasim was wrapped in a rug and trampled to death, marking the end of the Abbasids, one of the greatest Islamic dynasties.

Mongol Defeat at Ain Jalut

The war between the Mongols and the Turkish Mamluks marked a rare moment for the famously unstoppable Mongols. The Mamluks were an enslaved army loyal to the various Islamic state rulers. While they were technically enslaved, Mamluks could hold high status in Islamic society. At some points in history, members of the Mamluks were even installed as sultans over Egypt and Syria. As a fighting force, the Mamluks were well-equipped, elite warriors. Much like the Mongols, the Mamluks were especially skilled horsemen, but rode Arabian horses, which are much larger than the short, sturdy breeds used by the Mongols. Mamluks spent their whole lives in intensive training for all manner of combat: horseback archery as well as close-quarter combat with swords, lances, and clubs.

The Mongols, under Hulegu, marched on Egypt after they conquered Syria in 1260, and, like the sack of Baghdad, Hulegu sent a threatening letter to the Mamluk Sultan Qutuz before sending an army. However, Hulegu’s brother, Mongke, who was Great Khan at the time, had died and Hulegu had to return to Mongolia to decide the succession. But he left an army of 20,000 under his general, Ketbuqa.

At Ain Jalut in Gaza, the Mamluks took advantage of Hulegu’s absence and marched on this smaller Mongol army. Mamluks employed ambush tactics and made use of hand cannons to frighten the Mongol horses. While the Mongols and the Mamluks both suffered significant losses, the Mamluks managed to slaughter almost the entire Mongol Horde, including General Ketbuqa. This defeat forced the Mongols back to Iran and solidified the western Mongol border. While the Mamluks and Mongols would go on to fight further battles, the battle of Ain Jalut is significant for being the Mongols’ first significant defeat.