Drepung (Tibetan, 'dras-spung). One of the three great Gelukpa monasteries of central Tibet, located to the west of Lhasa and constructed in 1416 by Jamyang Chörje Trashi Palden ('jam-dbyangs chos-rje bkra-shis dpal-ldan). The combined religious and secular government of the Gelukpa school was established initially at the Ganden Palace in this monastery during the lifetime of Dalai Lama V and later achieved religio-political domination of the whole of Tibet. At its peak it housed some 20,000 monks. It was largely destroyed in the Cultural Revolution but has since been partly rebuilt.

A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)