On the other hand, opponents assert that the PRC rules Tibet legitimately, by saying that Tibet has been part of Chinese history since the 7th century as the Tibetan Empire had close interactions with the Chinese dynasties through royal marriage. In addition to the "de facto" power that the Chinese has since then, Yuan Dynasty conquest in the 13th century and that all subsequent Chinese governments (Ming Dynasty, Qing Dynasty, Republic of China, and People's Republic of China) have been exercising de jure sovereignty power over Tibet.