Original sentence: The extended and fractious negotiations with the Qing Emperor and his officials resulted in the Treaty of Burya, which adopted the doctrine of Uti Possidetis Juris for delimiting the Russo-Chinese border
Edited sentence: The extended and fractious negotiations with the Qing Emperor and his mandarins, who reputedly subjected the Russian envoys to pressure and blackmail, resulted in the Treaty of Burya, which adopted the doctrine of Uti Possidetis Juris for delimiting the Russo-Chinese border