The Derung (also spelt Drung or Dulong) people (; endonym: tə˧˩ɻuŋ˥˧ ə˧˩tsəŋ˥˧) are an ethnic group. They form one of the 56 ethnic groups officially recognized by China. Their population of 6,000 is found in the Nujiang Lisu Autonomous Prefecture of Yunnan in the Derung Valley of Gongshan Derung and Nu Autonomous County. Another 600 can be found east of the Derung Valley, living in the mountains above the Nu River (Salween River) near the village of Binzhongluo in northern Gongshan Derung and Nu Autonomous County. The Derung speak the Derung language, one of the Sino-Tibetan languages. Their language is unwritten; in the past the Derung have transmitted messages and have made records by making notches on wooden logs. There are few documents about the origins of the Derung. It is known, nevertheless, that during the period of the Tang dynasty, the Derung were under the jurisdiction of Nanzhao and the Dali Kingdom. The Derung Valley area, the southernmost part of Tsawarong, was known by the Tibetans as Changyul or Kiongyul, meaning the "valley of beer" because Derung people enjoy drinking. From the Yuan dynasty to the Qing dynasty, the Derung were governed by the local Tibetan or Nakhi rulers. They also paid yearly tribute to China; the local Lama, called Changputong, was in charge of sending it to Weixi. In 1913, the Derung helped to repel a British attack in the area. Prior to 1949, there were several other names used for this ethnic group; they were known as Qiao during the Yuan and Qiu and Qu during the Qing. Prior to the formation of the People's Republic of China, Derung society was based on a system of clans. A total of 15 clans existed, called nile; each one of them was formed by diverse familiar communities. Each clan divided itself into ke'eng, towns in which the Derung lived in common houses. Marriages between clans were prohibited. The typical dress of the women consists of a dress made of fabric lined with colors black and white. Formerly, the women used to tattoo their faces when they reached the age of twelve or thirteen.