In 1618, the Tsangpa Gyelpo pushed further into Ü and defeated the local leaders of Kyishö and Tsal. By now, Karma Phuntsok Namgyal was virtually the ruler of Central Tibet and was consecrated as such by
Chöying Dorje, 10th Karmapa. In the following year 1619, the West Tibetan kingdom of
Mangyül Gungthang was conquered. In the next year again Karma Phuntsok Namgyal returned to Ü in order to eliminate the last possible obstacle to his authority.
Nêdong, the seat of the impotent Phagmodrupa dynasty, was besieged and forced to yield to his power. Tsang forces occupied the entire
Yarlung Valley. The hegemony of Tsangpa was, however, only of a brief nature – their position as an upstart family without aristocratic roots made their authority tenuous. After Yonten Gyatso's death, his successor, the
5th Dalai Lama (1617–1682), received help from the Mongols, who pushed into Ü in 1621. The new Tsangpa king
Karma Tenkyong was defeated and besieged at Chakpori Hill by Lhasa, and his army only escaped annihilation through the intervention of the
Panchen Lama. An agreement was made whereby the Gelugpa regained much of their former authority in Ü. The abbot of the important
Drigung Monastery in Ü, allied to the Tsangpa, was abducted by the
Tumed Mongols in 1623, which was a further blow. In retaliation, Karma Tenkyong brought his troops to Ü and occupied the Lhasa region. The following years saw a lull in the fighting while both sides tried to attract allies. Karma Tenkyong sought the assistance of the
Choghtu Mongols, and a troop under prince Arsalan invaded Tibet in 1635 in order to attack the Gelugpa positions. However, in the end Arsalan declined to actually support the Tsangpa, leading to an entirely unsatisfactory conclusion of the enterprise for Karma Tenkyong and the Karmapa and Shamarpa hierarchs. At the same time, Karma Tenkyong was threatened by
Ladakh in the west, although it never came to open warfare. ==Triumph of the Dalai Lama==