The importance of travel in world history is obvious. Early travelerssome of whom we know about, more of whom we can only dimly fathom-helped make connections among regions in ways that had obvious cultural, commercial, and technological implications. They could help societies copy each other. They could encourage societies to forge regular interactions, establishing organized trade networks or regular student exchanges or the expansion of empires or tribute systems. While it is rarely easy to pinpoint the exact consequences of an individual voyage, the cumulative effect is clear enough.