Noghai

Nogai Khan was the head of the Golden Hoard, and at war with the Yuan Dynasty led by his archrival and kin, Kublai Khan. He sent Tegana to the Imperial Palace in Peking to talk with Kublai, wanting to report that he had forgiven him and their feud was over. However, Tegana had designs to assassinate and usurp the mighty ruler. (DW: Marco Polo)

Behind the scenes
In actual fact, Nogai Khan had no animosities towards Kublai Khan, it was his nephew, Kaidu Khan that was his sworn nemesis and antagonist for many years, synonchrous with the events of this serial. The producers merely stapled Nogai's name over Kaidu's for reasons unknown.