series of military campaigns – renowned for their brutality and ferocity – sweeping through much of Asia, and forming the Mongol Empire, the largest contiguous land empire in world history. Under his successors it stretched from present-day Poland in the west to Korea in the east, and from Siberia in the north to the Gulf of Oman and Vietnam in the south, covering some 33,000,000 square kilometres (13,000,000 sq mi), (22% of Earth's total land area) and having a population of over 100 million people. The emergence of Pax Mongolica also significantly eased trade and commerce across Asia during its height.
After Genghis Khan's death, the empire was subdivided into four kingdoms or Khanates which eventually became quasi-independent after Möngke's death in 1259. One of the khanates, the "Great Khaanate", consisting of the Mongol homeland and China, became the Yuan Dynasty under Kublai Khan, the grandson of Genghis Khan. He set up his capital in present day Beijing but after more than a century of power, the Yuan was replaced by the Ming Dynasty in 1368, with the Mongol court fleeing to the north. As the Ming armies pursued the Mongols into their homeland, they successfully sacked and destroyed the Mongol capital Karakorum among a few other cities, although some of these attempts were repelled by the Mongols under Ayushridar and his general Köke Temür.
After the expulsion of the Yuan Dynasty rulers from China, the Mongols continued to rule Mongolia, also referred to as the Northern Yuan. The next centuries were marked by violent power struggles among various factions, notably the Genghisids and the non-Genghisid Oirads, as well as by several Chinese invasions (like the five expeditions led by the Yongle Emperor). In the early 15th century, the Oirads under Esen Tayisi gained the upper hand, and even raided China in 1449 in a conflict over Esen's right to pay tribute, capturing the Ming emperor in the process. However, Esen was murdered in 1454, and
