First I sought wide and extensive learning,
Second I perceived all teachings as personal instructions,
Finally, I engaged in meditative practice day and night;
All of these I dedicated to the flourishing of the Buddha's teaching.
Tsongkhapa (1357-1419) was the founder of the Geluk school of Tibetan Buddhism. Although Geluk is the youngest of the four major Tibetan traditions (the other three being Nyingma, Sakya, and Kagyu), it rose to prominence on the strength of Tsongkhapa's innovative, rigorous, and comprehensive interpretations of Buddhist thought and practice.
Tsongkhapa's teaching helped stimulate a sophisticated appreciation of the importance trio of view, meditation, and conduct. In particular, his "Great Treatise on the Stages of the Path to Enlightenment" and a treatise on the stages of the Vajrayana path - powerfully brought home the importance of having the "big picture" while one is engaged in specific aspects of the Buddhist path. (excerpt from the book "Tsongkhapa A Buddha in the Land of Snows" by Thupten Jinpa and Foreward by His Holiness the Dalai Lama, 2019)