Mongol vs European
Guo Kan or Guo Khan (Chinese: 郭侃) (1217–1277) was a famous general of Han Chinese descent that served the Mongolian Khans in their Western conquests and the conquest of China itself. He was descended from a lineage of Chinese generals. Both his father and grandfather had served the Khan, while his ancestor is Guo Ziyi, a famed general of the Tang Dynasty.
He was one of the foreign legions that served for the Mongol Empire, and some of the later conquests of the Mongols were done by armies under his command. The biography of this Han Chinese commander in the Yuan Shi ("History of Yuan") said that Guo Kan's presence struck so much fear in his foes, that they called him the "Divine Man"!
Guo Kan was raised in the household of Prime Minister Shi Tianzhe (who was also a Han Chinese, and whose father and two brothers all served the Yuan).
He took part in the final drive in the conquest of the Jin Dynasty, including the capture of Kaifeng, and may have served in the European campaign with Subutai a few years following the fall of the Jin Dynasty. He then served in Hulagu's invasion of the Middle East, playing a major role in the capture and Battle of Baghdad, reportedly devising the strategy of using the dikes to drown the Caliph's army, and supervising the reduction of Baghdad's walls. He was then appointed Governor of Baghdad by Hulagu, and at some point after Khubilai Khan's accession as Khan, Guo Kan went to serve him, instead of his brother, and assisted Khubilai Khan in the conquest of the Southern Song, and ultimately the unification of China proper under the Yuan Dynasty.
The Yuan Shi is known to contain many errors. It is proven that many events after 1259 in Guo Kan's biography are false since he returned to Mongolia with Hulagu Khan after the death of Mongke Khan in China.
The Yuan Shi in many ways resembled historical fiction, claiming all manner of conquests by Guo Kan which were not true, but nonetheless were legend in China for many years. Contrary to claims in the Yuan Shi, the Mamluks of Egypt crushed the Mongol occupation army and their Christian allies at Ain Jalut led by Hulagu's lieutenant Ked-Buka; and the Crusader Kingdoms Mecca and Cyprus were neither conquered by the Mongols.
This biography of Guo is mostly open lies in what seems to be an attempt to hide the crushing defeats inflicted on the Mongols at Ain Jalut, and on Hulagu by Berke Khan in the first Mongol on Mongol war in the Transcaucasus. It must be noted that Ain Jalut took place while Guo Kan was in Mongolia with Hulagu during the selection of a Great Khan. Guo Kan, like Hulagu, had believed the force left to occupy Palestine was sufficient enough to deal with the Mamluks, which it was obviously not, and that the Il-Khanate could defeat the Golden Horde, which it equally could not.
After he returned to Mongolia with Hulagu Khan after Mongke Khan's death, Guo Kan was taken from Hulagu's command, and assigned by Kublai Khan to aid him in the difficult conquest of Southern Song Dynasty of China. Khubilai's accession as Khan left him able to select the best of the Mongol Generals to serve him. Subutai and Jebe were both dead of old age, and Guo Kan was the last of the dreaded Dogs of War, and the new Great Khan Khubilai assigned Guo Kan to commander the final conquest of China. Guo Kan reportedly urged him to adopt a Chinese-style dynastic title, establish a capital and central government, and build schools. He reportedly was the general who proposed capturing Xiangyang as a strategy for invading the Southern Song. He defeated Song forces in a battle at Xuzhou in 1262, and in 1266 urged Khubilai to establish military farms in Huaibei to provide supplies for an invasion of the Southern Song. In 1268 and 1270 he suppressed local rebellions, and then he was sent to participate in the siege of Xiangyang. In 1276, the Song dynasty fell (except for the loyalist movement that lasted until 1279), and Guo served as a prefect for one more year before dying.
More than any army in history until the 20th Century, and more so than many even in the Modern Era, the Mongols promoted strictly on the basis of military skill and ability. Like his brother "dogs of war," Jebe, son of an ordinary warrior in a tribe which had opposed Genghis Khan in his unification of the nomads, and Subutai, son of a blacksmith, Guo Kan, ethnically Han Chinese, represented the revolutionary concept of promoting the sons of the most humble, or foreign born, to command any of the Mongol nobility - including relatives of the Great Khan! Though Batu was nominally in charge of the invasion of Europe, it was Subutai who truly commanded. Equally, Guo Kan devised the strategy which reduced the powerful walls of Bagdad in mere days, after destroying her small, but brave and disciplined army in mere hours by drowning them. Merit, not birth, was one of Genghis Khan's most brilliant innovations, and Guo Kan, an ethnic of the Mongol's strongest rival, one of his prized dogs of war for five generations of Great Khans.