You are correct, Dharmaspace in your comments about the Mongolians. Historically the Mongolians were great supporters of Tibetan Buddhism and were great followers. As a matter of fact the title of Dalai Lama was bestowed by the Mongolians.
As such although they were conquerors and maybe barbaric, they honour what they have created, the Dalai Lamaship and yet did not forsake their devotion to Dorje Shugden, what a beautiful way to govern with religious and personal freedom. True Buddhist Practitioners.