The Mongols ruled with a strong sense of justice, summed up in their Yasa code and emphasized ability over lineage.
The Mongols themselves were assimilated into local populations after the fall of the empire, and many of these descendants adopted local religions—for example, the western Khanates adopted Islam, largely under Sufi influence.
Another advantage of the Mongols was their ability to traverse large distances even during harsh, cold winters; in particular, frozen rivers led them like highways to large urban conurbations on their banks.
Mongols prized their commercial and trade relationships with neighboring economies and they continued this policy during the process of their conquests and during the expansion of their empire.
In 1241-1242, during the Mongol invasion of Europe, Transylvania was among the territories devastated by the Golden Horde.
Descendants of the Mongols would also rule in India as the Moghuls, and in China through the Yuan Dynasty.
The thirteenth and fourteenth centuries, when the empire came to power, are often called the "Age of the Mongols."