What+are+the+sources+of+change+nomadic+migrations+vs.+urban+growth

Nomadic Migrations vs. Urban Growth Nomadic Migrations: Urban Growth: (under the Abbasids), Fujiwara moved capital of Japan to Heian, Mongols moved cap. to Samarkand, Malians moved cap to Timbuktu, and Maya moved cap to Tikal Indian Ocean trade, Silk Road trade, Hanseatic League, etc.
 * populations were growing and people needed more space to build bigger empires
 * huge movements of people (Germanic tribes into Southern Europe)
 * caravans of silk routes, Indian Ocean sailors, trips across Sahara to West Africa and trade in Mediterranean
 * better boats and roads, monetary systems, lines of credit, accounting methods
 * __Examples__: Eastern Roman Empire became Byzantine Empire (capital: Constantinople), Islamic empire moved to Baghdad
 * building of universities, thousands of people moved to new cities, and cultural diffusion caused constant trade:
 * Other key characteristics: water power, state-run factories, and paper currency

Sources: The Princeton Review 2008 edition, and Mr. Delarme's Notes