Answer:
The collapse of previously existing states, such as the Song dynasty of China
Explanation:
The Mongol Empire expansion covers areas such as present-day Mongolia, China, parts of East Asia like Southern Asia, Middle Eastern part, and Eastern Europe. This places Romania, Pakistan, Siberia, Ukraine, Burma, Russia, Belarus, and many others around the region. This expansion spanned around 1206 to 1294, it led to the collapse of previously existing states, such as the Song dynasty of China was between 960 to 1279.
