Those cities of the north—Balkh, Bukhara, Samarqand, Tashkent, and others—were entrepôts on the old Silk Road, which had long been the busiest highway of human commerce in the world, a network of roads and routes that connected China to Europe and both to India. People who lived in or around these cities traveled to India routinely on trading expeditions; and, of course, because people here were all Muslims, not a few had gone as far west as Mecca.
