The Drupchen is a festival dedicated to Bhutan's dominant female protective deity, Pelden Lhamo (Mahakali). Mahakali's consort Mahakala, a terrifying male protective deity black in color, inhabits cremation grounds. Just as all colors dissolve into black, all names and forms are said to melt into those of Mahakala, symbolizing his all-embracing, comprehensive nature. Though most of Pelden Lhamoi's dances are performed for the public in the Dzong's open courtyard, the Nangcham (secret ceremony) is held in her shrine’s inner sanctum, with monk-dancers circumambulating a sand mandala created to benefit all sentient beings. The principal and varied color emanations of Mahakala inhabit the center of this Mandala.
The festival was first introduced in Thimphu Dzong in 1710 by Kuenga Gyeltshen, recognized as Jampel Dorji's reincarnation, son of Zhabdrung Nawang Namgyel, founder of Bhutan. According to legend, Pelden Lhamo appeared in Kuenga Gyeltshen's dream and gave him several tantric teachings through dances.
Pelden Lhamo is chief of Mamos spirits—those wrathful feminine deities who keep pandemics, diseases, and famine at bay. Mamos are the natural forces that respond to environmental desecration by creating disaster and disease.