The Western Xia or Xi Xia (Chinese: 西夏; pinyin: Xī Xià; Wade–Giles: Hsi1 Hsia4; also known as the Tangut Empire, and known as Mi-nyak to Tanguts and Tibetans) was a Tangut-ruled empire and a dynasty of China which existed from 1038 to 1227 in what are now the northwestern Chinese provinces of Ningxia, Gansu, eastern Qinghai, northern Shaanxi, northeastern Xinjiang, southwest Inner Mongolia, and southernmost Outer Mongolia, measuring about 800,000 square kilometres (310,000 square miles). Its capital was Xingqing (modern Yinchuan), until its destruction by the Mongols in 1227. Most of its written records and architecture were destroyed, so the founders and history of the empire remained obscure until 20th-century research in China and the West.