Qin dynasty

The Qin Dynasty was a dynasty in China that flourished around 221 BC. (TV: The Angels Take Manhattan)

In 221 BC, the Eleventh Doctor and Amy Pond visited China to leave a message for River Song on a vase. To write the message, the Doctor used his psychic paper to convince ancient Chinese potters that he had special permission from the emperor. The message was the expression, "Yowzah", written in period Chinese script on a blue-and-white porcelain. (TV: The Angels Take Manhattan)

The Tenth Doctor and Donna Noble visited China during the Qin dynasty. (COMIC: The Immortal Emperor)

One of the ships used by the Eternals in their contest for Enlightenment was a Chinese ship crewed by Chinese sailors from the Qin Dynasty. (TV: Enlightenment)

Behind the scenes
In the real world, blue-and-white porcelain did not exist in the Qin Dynasty, but in Qing Dynasty, which ruled China proper from 1644 to 1912.