Excerpts from Books and Wikipedia
"The Mongol Empire emerged in the course of the 13th century by a series of conquests and invasions throughout Central and Western Asia, reaching Eastern Europe by the 1240s. The speed and extent of territorial expansion parallels the Hunnic/Turkic conquests of the Migration period (the 6th century Turkic Khaganate). The territorial gains of the Mongols persisted into the 14th century in China (Yuan Dynasty), into the 15th century in Persia (Timurid dynasty) and in Russia (Tatar and Mongol raids against Russian states), and into the 19th century in India (the Mughal Empire)." [Wikipedia] "Between 1246 and 1264, the Mongols spread their conquests from east to west, but then watch the empire divide into four. . . . Kublai still ruled in the east, but the Golden Horde khanship and the Chagatai Khanate would continue to claim their independence. Hulagu’s own conquests, growing apart from the other Mongol lands, would become the Il-khanate, a separate Mongol kingdom in the Middle East. The empire that had stretched from the Chinese coast to the Black Sea had fractured into quarters. . . " [Bauer: Renaissance World, p. 339-343]