Apparently, according to one partially damaged scroll from Dunhuang, there was hostility between Sa-tha-ma-kar and Songtsen Gampo's younger brother, bTzan-srong, who, as a result, was forced to settle in gNyal (an old district to the southeast of Yarlung and across the 5090 meters Yartö Tra Pass, which bordered on modern Bhutan and Arunachal Pradesh in India).