“Rendawa Shunu Lodrö specialized in the Madhyamaka philosophy, the Middle Way school. He wrote many books on Madhyamaka. Rendawa Shunu Lodrö was also the main teacher of Lama Tsongkhapa, the founder of the Gelug school. Lama Tsongkhapa studied under Rendawa for many years.”
Extracted from An Overview of the Sakya School of Tibetan Buddhism: History, Masters, and Teachings, by H.H. the Sakya Trichen; The Sakya Tradition Publications.