During the reign of the seventh-century king, Songtsen Gampo, Tibet was one of the mightiest empires in Central Asia. Tibet, then, had an army of 2,860,000 men. Each regiment of the army had its own banner. The banner of Ya-ru To regiment had a pair of snow lions facing each other, that of Ya-ru Ma a snow lion standing upright, springing upwards towards the sky, and that of U-ru To a white flame against a red background.