During my stay in Tibet from 1946 to 1950 I undertook to edit the late Sir Charles Bell's material on the inscriptions at Lhasa and Bsam Yas. This work led me to try to trace as many ancient Tibetan inscriptions as possible, and my inquiries took me to the rdo riṇs at Mtshur Phu, Saṅs Rgyas Dgon-pa, Hphyoṅ Rgyas, and Žva-ẖi Lha Khan, as well as to many likely but unproductive sites such as ẖu Žaṅ and Lha-Khaṅ Rdzoṅ. I also heard vague rumours of an old inscription somewhere near Rtse Bla Sgaṅ, on the Gtsan-po (Brahmaputra). As it would have needed more than six weeks' absence from my duties at Lhasa, I was not able to visit the place myself but I eventually enlisted the help of the young but very learned Bkaẖ Rgyud-pa Lama, Bdud ẖjoms Rinpoche, whose monastery is in that area and who was engaged on building a new lha-khan at an ancient site called Zans Mdog Dpal Ri. He had seen the inscription which, he said, was carved on a pillar or rock face beside the track along the north bank of the Gtsan-po, in an area known as De-Mo Sa. It was said to be sheltered by shallow stone walls supporting tiled eaves and to be almost completely buried in sand. The few lines which were visible were reported to refer to Khri Sroṅ Lde Brtsan and to contain the words “Kon Jo”, from which local tradition assumed that it referred to the Chinese princess who was (incorrectly) said to be the mother of Khri Sroṅ Lde Brtsan.