The Suru Valley is a valley in the Kargil District in the Union Territory of Ladakh, India. It is drained by the Suru River, a tributary of the Indus River. The valley's most significant town is Sankoo. Horses, yaks and other animals can be found in the valley. In winter Suru Valley experiences heavy snowfall and avalanches. The literacy rate of Suru Valley is very low as compared to other parts of Ladakh. History The Suru Valley was historically ruled from Kartse (, ), a fort in a branch valley near Sankoo. An inscription names its ruler as Tri-gyal (). Tibetologist A. H. Francke believes that the dynasty of Tri-gyals might have been in existence prior to the formation of the Maryul kingdom (in modern Ladakh) in the 10th century. However, there is no mention of it in Ladakh Chronicles. When the Maryul kingdom was formed under Lhachen Palgyigon, its extent ran up to the Zoji La pass. The principality of Kartse apparently controlled the entire western Ladakh, from Mulbekh and Wanla in the east to Dras in the west, even though the extent of territory would have varied with time. The Tri-gyals were Buddhist and adopted the religion from Kashmir in ancient times. They commissioned a giant Maitreya rock carving in the vicinity of Kartse, and others at Mulbekh and possibly Apati. The conversion of Kashmir to Islam in the 14th century had implications for western Ladakh. Baltistan was invaded during the reign of Sultan Sikandar (), and the influence of Islam spread there. Zain-ul-Abidin () raided Ladakh, Guge and Purang (in western Tibet) and collected tribute. The Tri-gyal of Kartse is said to have become his vassal and assisted in the invasions. Some time after this, a Muslim chieftaincy connected to Skardu appeared in Purig, first at Sod northeast of Kargil, then with a branch at Chiktan northeast of Namika La. During the invasion of Ladakh by Mirza Haidar Dughlat in 1532, Sod and Chiktan appear to have submitted, but not Kartse. Joint raids were conducted on Kartse but they failed. The chief or commander of Suru, named "Baghan", is also said to have been killed during one of the raids. A succession of Ladakhi kings from Tashi Namgyal () onwards attempted to make forays into Purig, but Kartse is not mentioned by name until the time of Deldan Namgyal (). Deldan Namgyal, having made peace with Lhasa