Cave paintings in the Bayankhongor Province of Mongolia dating back to Neolithic age of 7000BC show grappling of two naked men and surrounded by crowds. The art of Bökh appears on
bronze plates discovered in the ruins of the Xiongnu empire (206 BC–220 AD). Originally, Bökh was a military sport intended to provide mainly strength, stamina and skills training to
troops. Genghis Khan (1206–1227) and the all later Emperors of the Mongol Empire (1206–1368) and also the Emperors of later Khanates were keen to support the sport for this reason
so wrestling events were included in local festivals, or Naadam. Wrestling became a key factor when deciding the candidate rankings in imperial martial exams plus outstanding
wrestlers were entitled to high distinctions.
(source citation en.wikipedia.org )