The Indian subcontinent has three main reasons: Himalaya Mountains, southern peninsula and Indo – Gangetic plains.

    • Regional differences and related separate identities greatly fostered by geography, have stood in the way of the rise of durable pan Indian states in Indian history.
    • Never was the whole subcontinent a single political unit.
    • The Himalayas in the North and northwest and the Indian ocean in the south create a superficial view of isolation of the country from the subcontinent.
    • However the most difficult terrain does not impede the movement of ideas and influences between the people. Cultural influences have been exchanged across the frontiers and there have been maritime contacts with the west, West Asia and South east asia from the earlier times.

Himalayan mountains: 

  • The mountains stretch from Pamir in the North West to north east. It has a length of 2560 km and breadth of 240-320km.
  • The Himalayas protect Indian subcontinent from cold winds blowing from Siberia to central Asia.
  • The Himalayas also protect against external invasions but the passes Khyber, Gomal, Khurram and Bolan allow easy access.
  • The Greeks, Huns, Parthian’s, Turks and Sakas entered the subcontinent through these. Alexander came through the Swat valley. These passes allowed trade as well as cultural contacts between India and central Asia.
  • In the east the Himalayas have thick forests and heavy rains and thus many regions of the Himalayas are isolated from rest.

Indo Gangetic Plains: 

It is a very fertile region irrigated by Ganga, Yamuna and Brahmaputra. Thar Desert and Aravalli hills are located between Ganga and Indus plains. Area between two rivers is called “doab“.

Many urban centres are located at the confluence of rivers and river banks. Most important urban centre is Delhi on the western side of Gangetic plain.

The plain is a source of temptation and attraction to foreign invaders due to its fertility and productive wealth. Important battles were fought to conquer these plains especially the Ganga Yamuna doab was the most coveted and contested battle.

Kurukshetra and Panipat were most common battles grounds.

The rivers in these regions are arteries of commerce and communication. 

Southern Peninsula: 

  • The Vindhya and Satpuda mountain ranges along with Narmada and Tapti rivers form the dividing line. The plateau to the south of it is Deccan plateau which is of volcanic rock.  As the rocks are easier to cut many rock cut temples and monasteries are found here.
  • The Deccan plateau is flanked by Eastern and Western Ghats.
  • The Coromandel Coast is located between Eastern Ghats and Bay of Bengal. The Western Ghats and Eastern Ghats meet at Nilgiri hills.
  • The Deccan plateau is bridge between north and south but due to the dense forests in the Vindhyas the culture and language is well preserved due to geographic isolation.
  • In the south, Palghat pass from Kaveri valley to Malabar Coast was famous for Indo – Roman trade. The Eastern Ghats are low and cut in places due to fast flowing rivers. The rivers of the southern peninsula flow from west to east except Narmada and Tapti which flow from east to west. The rivers flow parallel to each other.
  • The Krishna Tungabhadra doab has been hotly contested by southern kingdoms due to its fertility. Due to the long coastline the south kingdoms developed cultural and commercial relations with Greco – Roman kingdoms.