In 1236 a large Mongol army was collected under the supreme leadership of Batu Khan and set forth to the west, in one of the greatest invasions in world's history.^[56] Although some Cuman groups survived the Mongol invasion, the Cuman aristocracy was slain.^[58] The steppes of eastern Europe were conquered by Batu Khan's army and became parts of the Golden Horde.^[57] But the Mongols left no garrisons or military detachments in the lower Danube region and did not take direct political control of it.

After the Mongol invasion, a great many (if not most) of the Cuman population left the Wallachian Plain, but the Vlach (Romanian) population remained there under the leadership of their local chiefs, called knezes and voivodes. In 1241, Cuman domination was ended—a direct Mongol rule over Wallachia was not attested. Part of Wallachia was probably briefly disputed by the Kingdom of Hungary and Bulgarians in the following period,^[59] but it appears that the severe weakening of Hungarian authority during the Mongol attacks contributed to the establishment of the new and stronger polities attested in Wallachia for the following decades.^[60]