In 600 CE, a dynamic and living religious society was brought to existence. After Muhammad's death, the Islamic caliphate built dar al-Islam the Muslim community from conquests made by the Arabs. Muslim cities were sprouting throughout the Mediterranean region, and trade extended into Asia. During the Post-Classical era, Islamic civilizations made noteworthy impacts in the Muslim society, undertaking military expansions that stretched its political and cultural influences through trade and missionaries. One city after another, the huge Islamic realm was coming together. From the very beginning, Islamic society prospered primarily from commerce and manufacturing. During the Abbasid caliphate, intricate trading networks linked and unified all regions of the Islamic world, creating a hemispheric trading zone as seen in Document 8. Scholar Abd al-Rahman once stated there were skilled workmen in Nishapur and Merv, and that Samarkand was the destination of merchants (Doc. 7). Nishapur, Merv, and Samarkand were habituated commercial centers where merchants traded through the silk roads, built in the classical era, which stretched from the Mediterranean region to China. In 1275 CE, Marco Polo, an Italian merchant, traveled through the silk roads network and observed the city of Tabriz and its nobility. The city was the most well-known and populous of the province of Azerbaijan, which contained many other grand and fortified cities. Polo noticed that the people primarily supported themselves through commerce and manufactures (Doc. 5). He said it was so advantageously situated for trade that merchants from India, Mosul, and Hormuz, as well as parts of Europe, come to purchase and to sell. This is also because agricultural production was growing and this contributed to rapid urbanization of the Islamic world. Land travel was typically on camel caravan because of its high endurance and ability to carry heavier loads than horses or donkeys.