This large and impressive painting depicts Chaturmukha Mahakala, the four-faced form of the deity associated with the Manjuvajra Guhyasamaja tantra lineage of practice. The Guhyasamaja lineage originated as a Sakya tradition, though was embraced by the Gelug School, under which this painting was commissioned.
This black ground painting, with an astonishing amount of color, aligns with the Tashilhunpo style of painting, most evidenced by the stylization of the leaves and flowers surrounding the ancillary figures. Remarkably, every figure in the painting carries its own identifying inscription.
Wrathful in appearance, the central deity holds a curved knife and kapala in his primary hands and a sword and spear in his raised hands. He is surrounded by the four attendant dakinis - Dombini, Chandali, Rakshasi and Singhali Devi, all depicted with different colored skin. Paintings on black ground are used to depict wrathful and semi-wrathful deities. This particular example of a black thangka is especially notable for its vivid palette, excellent condition and large size.