IT may look deceptively similar to Chinese. But, for more than a century, the strange script used by the former Tangut empire of Tibetan Buddhists has baffled scholars the world over.
Now a mainland professor, Li Fanwen, who only escaped death during the Cultural Revolution because he is one of the few who understands this dead language, has unlocked its secrets by producing the first complete dictionary to translate it.
The first traces of Tangut appear to have been found in the late 19th century, when Russian explorer Colonel Pyotr Kozlov stumbled across a ruined city forgotten in the Mongolian desert, the abandoned outpost of an unknown empire.
Kozlov returned several times to explore the ruins of the abandoned city of Khara Khoto, the Black City. Not far from the city walls in the ruins of a temple stupa, he found a cache of manuscripts written in a strange language with characters that resembled Chinese and which he took back to St Petersburg.
Khara Khoto was mentioned by Marco Polo in the 13th century and while its walls still exist, they are now being engulfed by desert sands. The Edzin-Gol River (known as the Ruo Shui River in China) and the lakes which nourished its population have dried up.
The turn-of-the-century scramble by European and Japanese explorers to dig up the treasures of the Silk Road and unravel the mysteries of its civilisations has been followed by a competition to unlock the secrets of the documents found at Khara Khoto and elsewhere.
Kozlov gave his treasures - about 3,500 items, including 400 books and 300 paintings - to the Hermitage Museum in St Petersburg, but the Russian communists stored them in Kazan Cathedral which they renamed the Museum of Religion and Atheism. There they remained, mostly undisturbed until the Glasnost era. In 1990 a major exhibition was mounted.