Purported flag of the w:en:Mongol Empire
WARNING: This image is highly speculative. the source cited by fotw is not a reliabls scholarly reference. This image should not be added to articles about the Mongol Empire. If it is added anyway, then its speculative nature must be a clearly indicated. Note that fotw is based on user contributions like Wikipedia, and hence not authoritative either.
https://www.fotw.info/flags/mn-early.html
Martin23230