At its height the T'ang Dynasty ruled a vast area of Asia, that included Manchuria and Korea as tributary states. Control of almost half of the Silk Road trade routes greatly increased the coffers of the empire as well as helped spread the advances of this powerful dynasty. The rule of the T'ang was a period of cultural advancement, social stability and creative inventions. Three of the greatest inventions during the T'ang rule would have massive effects on the rest of World history: block printing, paper money and gunpowder. T'ang ruler Wu Zetian (625-705) is the only acknowledged female Emperor of China. She attained this exalted position through sex, lies, spies and murder (very traditional ways to take power throughout history). Once in total control she was a good, benign ruler choosing the best adviser's possible to run her government. A major change in the country was when she made Buddhism the official religion over Daoism in the Empire.