The usage of gold testifies to the prosperity of the Kushan Empire from the time of Vima, being the center of trade between the Han Dynasty of China (where Vima was known as 阎膏珍), Central Asia and Alexandria and Antioch in the West. The Kushan were able to maintain and protect the Silk road, allowing silk, spices, textiles or medicine to move between China, India and the West. In particular, many goods were sent by ship to the Roman empire, creating a return flow of gold coins, Greek wine and slaves. Works of arts were also imported from all directions , as indicated by the variety and quality of the artefacts found in the Kushan summer capital of Bagram in Afghanistan. A strong artistic syncretism was stimulated, as indicated by the Greco-Buddhist art of Gandhara.