Following the Han Dynasty (202 BCE–220 CE) emissary Zhang Qian's exploration of the Western Regions in the 2nd century BCE and contact with Hellenistic kingdoms such as Fergana, Bactria, and the Indo-Greek Kingdom, high quality grapes were introduced into China and Chinese grape wine (called putao jiu in Chinese) was first produced. However, rice wine remained the most common wine in China, since grape wine was still considered exotic and reserved largely for the emperor's table during the Tang Dynasty (618–907), and was not popularly consumed by the literati gentry class until the Song Dynasty (960–1279).The fact that rice wine was more common than grape wine was noted even by the Venetian traveler Marco Polo when he ventured to China in the 1280s. As noted by Shen Kuo (1031–1095) in his Dream Pool Essays, an old phrase in China amongst the gentry class was having the company of the "nine guests" (jiuke), which was a figure of speech for drinking wine, playing the Chinese zither, playing Chinese chess, Zen Buddhist meditation, ink (calligraphy and painting), tea drinking, alchemy, chanting poetry, and conversation.