Within the Gelug tradition, the so‑called “Three Great Seats” near Lhasa form the backbone of its institutional and spiritual life. Ganden Monastery, founded by Tsongkhapa in 1409, stands as the mother monastery and original seat of the school, housing the Ganden Tripa, the official head of the Gelug lineage. It became the primary locus for the study and practice of Tsongkhapa’s systematic teachings and preserved his relics. Drepung Monastery, founded in 1416 by Jamyang Chöjé, grew into the largest monastery in Tibet, at times housing many thousands of monks and serving as a major center of scholastic training. Sera Monastery, established in 1419 by Jamchen Chöjé Shakya Yeshe, gained renown for its highly formalized debate tradition and rigorous curriculum, producing generations of scholars and teachers. Together, these three institutions shaped the intellectual culture, discipline, and leadership structures that came to characterize the Gelug school.

Beyond these great seats, several other monasteries carried the Gelug vision into different regions and lineages. Tashilhunpo Monastery, founded in 1447 by Gendün Drub, the First Dalai Lama, became the seat of the Panchen Lamas and an important center of both spiritual authority and regional influence in Tsang. Labrang Tashikyil Monastery, established in 1709 by the first Jamyang Zhepa in Amdo, emerged as one of the largest and most important Gelug monasteries outside central Tibet, serving as a bridge for Gelug teachings across northeastern Tibetan areas and neighboring cultures. Kumbum Monastery, founded at Tsongkhapa’s birthplace in Amdo, likewise functioned as a major center for the transmission and study of Gelug doctrine in that wider region. Through these monasteries, the Gelug school extended its reach, not only preserving Tsongkhapa’s reforms but also nurturing a network of learning, ritual, and governance that deeply marked the religious landscape of Tibet and its borderlands.