Answer:
The most relevant legacy of Mongols conquest in the Eurasia region was a period of peace called: Pax Mongolica.
However, the most popular sociological change came along the spread of the bubonic plague that was a virus from the fleas that live on marmots in the steppes.
Explanation:
Pax Mongolica was the peace period experience as the frontier countries to Mongol territory did not want conflict with them. This century 1280-1360 strengthen the silk road, which was a vast trade route exchanging goods between Europe and China.
Along the prosperity of the silk road the bubonic plague was brought to Europe killing the 25% of Europes population.