Feng's team chose items that place this era in its global context. For example, a gold-gilt silver vase from a Northern Zhou Dynasty (557-581) high official Li Xian's tomb displays Greek decorative patterns typical of the Trojan War. The vase, which dates to about half a century before the Zhenguan era and which was found in present-day Guyuan in the Ningxia Hui autonomous region, demonstrates a willingness for contact with faraway lands.

Also from Guyuan, a group of Byzantine gold coins bearing the head of Justinian the Great dating to the Northern Zhou period may hint at international trade along the Silk Road before it reached its zenith following the Tang era.

Many other exhibits from the Tang Dynasty, including gold decorative fillets, glass bowls, turquoise ornaments, and stone carvings with Sasanian patterns, all remain as evidence of cross-cultural communication, echoing the open nature of the Zhenguan era.

According to ancient records, Li Shimin received envoys from all over the world in a grand ceremony in Chang'an in 639, adding a new chapter to the tale of the city as a crossroads of the ancient Silk Road.

"The light of the Tang Dynasty shone brightly on the stage of world civilization," Feng says. "It left references for national governance during dynastic periods."

"Using the Zhenguan era as a mirror, we are able to better understand how civilizations rise and prosper," she adds.