Geography affects and has affected the Indian subcontinent physically, politically, religiously and culturally. On land, geography affected migration routes and languages. Historically, the sea has played an important role in trade and contact with the outside world.
The Indian subcontinent today includes India, Pakistan, Nepal, Bhutan and Bangladesh. The north is home to a largely flat area that's home to three of the world's great rivers: the Indus, the Ganges and the Brahmaputra. The Himalayas are the source of all three and provide water to more than 1 billion people.
Islam is the majority religion in Pakistan and Bangladesh; a sizable percentage of people in northern India also follow Islam. Southern India is home to the Deccan Plateau and several great rivers, and was home to many of the region's first indigenous peoples. The south remained largely unscathed by the Muslim invasions of the north. Here, Hinduism is the predominant religion and many of the languages are in a different language family than those of the north.
The sea has affected the Indian subcontinent as much as the land. Sea trade with the European world established contact with British, Dutch, Portuguese, French and Danish companies. The first Muslims arrived by sea from Arabia. Today, geography mostly affects the subcontinent in terms of borders and political disputes, as in India-Pakistan relations and the Kashmir dispute.