The vast Gobi plain, which extends for miles along the steep Helan Mountains, is studded with nine 20-metre-tall clay pagoda-style pyramids as well as hundreds of smaller ones. They stand there in mute witness to the rough winds that scour the surface year round, coming in from deserts around the tiny Ningxia Hui Autonomous Region. These silent sentinels are imperial tombs of Xi Xia, a powerful empire set up by ethnic Tanguts in 1038. The Chinese word Ningxia in fact means 'peace and stability after [the defeat of] the Xia.' Today, nearly 800 years after the fall of that empire, the ruins are one of Ningxia's major tourist attractions and get thousands of visitors every year. That has also added some fashionable changes to the Muslim neighbourhood, where Buddhist structures have been repaired, Central Asian style dances are performed, and the strange character-like ideograms with sloping strokes that were widely used as decorations are restored. But, there is also a story of academic hardship and political conflicts behind the work of restoring this lost culture. The person to talk to about that is Li Fanwen, of Ningxia University. The 70-year-old scholar is one of a handful of people in the world who can read and speak the Tangut language. By 1227, Xi Xia had spent 190 years fighting fiercely against larger more powerful groups like the Han, Khitans, Jurchens, Uygurs and Tibetans and was finally crushed by Genghis Khan who was enraged by their tough resistance. So, the Mongols annihilated most of the remaining Tanguts and looted and burned the imperial tombs, obliterating almost all historical evidence of the state. In 1909, the culture was rediscovered by a Russian explorer in Khara Khoto ('Black Town') on the edge of the Gobi Desert. He found 8,000 relics, including fragments of a Han-Tangut dictionary, which helped in decoding some of the mysterious script. Most of the 8,000 relics were carted off to Russia but some were handed over to the last emperor of China. The Russian research on Xi Xia came to an abrupt and untimely end in 1938 when two researchers were executed during the purges under Josef Stalin. But research continued in China. Mr Li first got a look at some of these texts in 1954 when he was studying in Beijing. He fell immediately in love with the 'enchanting' characters and, knowing that present-day Ningxia had been in the centre of the state, in 1960, he applied to go study the culture there. That was the period of great famine and he came near to dying. He was always left with so few resources for fieldwork that he never actually saw the barren sentinels just outside the regional capital of Yinchuan during the 1960s. At this stage Mr Li had no knowledge of the existence of the tombs so he was unable to provide any protection for them. Some of the local herdsmen used the earthen enclosures around them as pens for their sheep and goats and some local work units built water towers on one of them. When the air wing of the People's Liberation Army slowly moved into the region in the 1960s, the earthen mounds were too good to resist as a target for their weapon practice. The coup de grace came for many of the ruins when an airport was built nearby. 'It's a great pity because the ones that were destroyed might have been some of the main imperial tombs that are missing,' says Mr Li. The Xi Xia had 12 emperors in all, but only nine of their tombs have been found. But, there was a stroke of good luck for the tombs and Mr Li in the early 1970s when some Soviet researchers published a paper claiming that Xi Xia was an independent state and that its culture was of Central Asian origin instead of Chinese. To counter-act this argument, the Chinese government sponsored its own large study, which lead to the excavation of the imperial tombs, in 1972. Most of the tombs had already been robbed long before that, but archeologists were still able to recover some beautiful relics, including some fabulous stone monsters of unknown origin, a stone figure of a Tangut minister, and the largest gold-plated copper ox in China. There were also 3,000 steles unearthed and Mr Li recorded 5,800 of the strange characters. Then, after years of tedious, painstaking research, he finally managed to decode all of them and compile a comprehensive Tangut-Han dictionary. 'The characters were created in a highly regular way and served the three to five million people of Xi Xia well for nearly 200 years,' he said. The name Xi Xia has taken on some odd new meanings in recent years and there are at least 100 local items ranging from liquor to jewellery and garments to cement that bear the name as a trademark and sign of quality. The partially decoded mystery of Xi Xia has drawn an increasing number of visitors and the combined Muslim and Buddhist cultures of the region are one of the main attractions. 'It is quite natural, there are many mosques in other places, but Xi Xia can only be seen here,' Mr Li said. Those in Beijing also give more appreciation of these long-forgotten tombs. They have just allocated 20 million yuan (about US$2.45 million) on the protection of the tombs and part of the money has been used to cover the pyramid of the founder of Xi Xia with a special kind of glue that is said to be able to resist erosion. No one can feel the pulse of this change more than Mr Li, who struggled with little or no support for years. One good sign was the recent reassurance he got from the regional Communist Party chief of full support. Even local enterprises contact him for business ideas. One of them was a company listed on the stock exchange that wanted to discuss a plan to restore part of the ancient Xi Xia capital and have Mr Li be the head of a new Xi Xia Research Institute there. The debate between China and the Soviet Union about the origin of Xi Xia culture died down some time ago with no clear results and Mr Li has never felt more liberal in his Xi Xia research. However the old ghosts of disputes over historical truth return to haunt occasionally. Several years ago, the first TV drama about the founding of Xi Xia was being filmed with Mr Li's assistance, but someone got wind of it and wrote a letter to the central government saying that it might undermine national unity (because of the suggestion of a strong rival empire). Production was halted immediately. 'Xi Xia never tried to bring the Han under its rule and it had the right to oppose the corrupt rulers in China,' Mr Li said on a final note.