In the 17th century , during the reign of the Fifth Dalai Lama , Key was attacked again by the Mongols .
In the 17th century , during the reign of the Fifth Dalai Lama , Key was later became a Gelugpa establishment .
In the 17th century , during the reign of the Fifth Dalai Lama , Key was attacked again by the Mongols and later became a Gelugpa establishment .