Tsang is the western part of Central Tibet (Ütsang), which it constitutes together with its eastern part, Ü. In the twelfth through fourteenth century it was the political center with the alliance with the Mongolian Empire struck by leaders of the Sakya (sa skya) tradition based in the Sakya region of southern Tsang. Subsequently political power shifted to the northeastern parts of Tsang, including most importantly Rinpung (rin spungs), Gyantsé (rgyal rtse), and Zhikatsé (gzhis ka rtse). Tsang rule over the entire region was finally ended by the Fifth Dalai Lama’s Ü-based triumph in the seventeenth century.