This mask is part of a costume worn during tsam dances in Mongolia. This particular costume depicts Begtse, the main protector deity of Mongolia. Begtse was the God of War in pre-Buddhist Mongolia. This stunning work of art is now in the Choijin Lama Museum in Ulaan Baatar. The Choijin Lama was the State Oracle of Mongolia and the brother of the Eighth Bogd Gegen, the Buddhist ruler of Mongolia prior to the Communist Revolution of 1921.