Although people, ideas, and goods had been traveling across Eurasia for millennia, the historical Silk Road is considered to have been established in the 2nd century B.C.E. when a Chinese envoy journeyed into Central Asia in search of horses and allies to fight marauders on the borders of China. Soon afterward, Buddhism began to spread from India north along Silk Road land routes to Central Asia, China, Korea, and Japan and south by sea routes to Southeast Asia. Buddhist art and architecture, of course, were transmitted along with the religious doctrines. One of the major architectural monuments of Buddhism is the stupa, in India a solid ...