Islam's impact was the most notable in the expansion of trade. The first contact of Muslims in India , was the Arab attack on a nest of pirates near modern-day Bombay , to safeguard their trade in the Arabian sea Around the same time many Arabs settled at Indian ports, giving rise to small Muslim communities, the growth of Muslim communities was not only due to conversion, but also the fact that many Hindu kings of South India (such as those from Cholas) hired Muslims as mercineries.
A significant aspect of the Muslim period in world history was the emergence of Islamic Sharia Courts capable of imposing a common, commercial and legal system that extended Morocco in the west to Mongolia in the North-east and Indonesia in the souh east. While southern India was already in trade with Arabs/Muslims, northern India found new opportunities . As the Hindu and Budhist kingdoms of Asia were subjugated by Islam, and as Islam spread through Africa - it became a centralizing force that facilitated in the creation of a common legal system that allowed letters of credit issued in say Egypt or Tunisia to be honoured in India or Indonesia (The Sharia has laws on the transaction of Business with both Muslims and Kaffirs). In order to cement their rule, Muslim rulers initially promoted a system in which there was a revolving door between the clergy, the administrative nobility , and the mercantile classes.
The travels of explorer Muhammad Ibn-Abdullah Ibn-Bututa were eased because of this system. He served as an Imam in Delhi, as a judicial official in the Maldives in the Maldives and as an envoy and trader in the Malabar. There was never a contradiction in any of his positions because each of these roles complemented the other. Islam created a compact under which political power, law and religion became fused in a manner so as to safeguard the interests of the mercantile class. This led world trade to expand to the maximum extent possible in the medieval world.
Sher Shah Suri took initiatives in improvement of trade by abolishing all taxes which hindered progress of free trade . He built large networks of roads and constructed Grand Trunk Road which connocted Calcutta to Kabul, of which parts of it are still in use today.
