Final answer:
After Genghis Khan's death, his descendants continued his conquests, expanding the Mongol Empire across Europe, the Middle East, and China. However, the empire eventually declined and disintegrated due to internal conflicts and the spread of the Black Death.
Step-by-step explanation:
After the death of Genghis Khan, his descendants continued his campaign for conquest. His sons and grandsons completed the conquest of Europe, the Middle East, and China. However, the Mongols never invaded Europe despite their victories in battles against European armies. Eventually, the Mongol Empire started to decline and disintegrate due to infighting among Genghis Khan's descendants and the impact of the Black Death.