Lochen Rinchen Zangpo (958–1055; ), also known as Mahaguru, was a principal lotsawa or translator of Sanskrit Buddhist texts into Tibetan during the second diffusion of Buddhism in Tibet, variously called the New Translation School, New Mantra School or New Tantra Tradition School. He was a student of the famous Indian master, Atisha. His associates included (Locheng) Legpai Sherab. Zangpo's disciple Guge Kyithangpa Yeshepal wrote Zangpo's biography. He is said to have built over one hundred monasteries in Western Tibet, including the famous Tabo Monastery in Spiti, Himachal Pradesh, Poo in Kinnaur and Rinchenling monastery in Nepal. Rinchen Zangpo had been sent as a young man by King Yeshe-Ö, the ruler of Zanskar, Guge, Spiti and Kinnaur, with other young scholars to Kashmir and other Buddhist centres to study and bring back Buddhist teachings to Western Tibet. He was possibly the single most important person for the 'Second Propagation of Buddhism' in Tibet. Some sources conflate him with his patron Yeshe-Ö as king of the western Himalayan Kingdom of Guge. Among his translations are the Viśeṣastavaṭikā by Prajñāvarman, which he undertook together with Janārdhana.