The Mongols after Genghis Khan We can divide Mongol expansion after Genghis Khan’s death into two distinct phases: the first which spanned the years - when the major gains were in the Russian steppes, Bulghar, Kiev, Poland and Hungary. The second phase including the years - led to the conquest of all of China ( ), Iran, Iraq and Syria. The frontier of the empire stabilised after these campaign. The Mongol military forces met with few reversals in the decades after but, quite noticeably, after the 1260s the original impetus of campaigns could not be sustained in the West.
Although Vienna, and beyond it western Europe, as well as Egypt was within the grasp of Mongol forces, their retreat from the Hungarian steppes and defeat at the hands of the Egyptian forces signalled the emergence of new political trends. There were two facets to this: the first was a consequence of the internal politics of succession within the Mongol family where the descendants of Jochi and Ogodei allied to control the office of the great Khan in the first two generations. These interests were more important than the pursuit of campaigns in Europe. The second compulsion occurred as the Jochi and Ogodei lineages were marginalised by the Toluyid branch of Genghis Khanid descendants.
With the accession of Mongke, a descendant of Toluy, Genghis Khan’s youngest son, military campaigns were pursued energetically in Iran during the 1250s. But as Toluyid interests in the conquest of China increased during the 1260s, forces and supplies were increasingly diverted into the heartlands of the Mongol dominion. As a result, the Mongols fielded a small, understaffed force against the Egyptian military. Their defeat and the increasing preoccupation with China of the Toluyid family marked the end of western expansion of the Mongols.
Concurrently, conflict between the Jochid and Toluyid descendants along the Russian-Iranian frontier diverted the Jochids away from further European campaigns. The suspension of Mongol expansion in the West did not arrest their campaigns in China which was reunited under the Mongols. Paradoxically, it was at the moment of its greatest successes that internal turbulence between members of the ruling family manifested itself. The next section discusses the factors that led to some of the greatest successes of the Mongol political enterprise but also inhibited its progress.