Bangla, Bangali or Bengal, the regional culture and language received its distinct identity from 10th century CE onwards. However, the mention of the place can be traced to epics like Mahabharata. 14th-century Moroccan traveler Ibn Batuta described Bengal as 'land with abundance'. 16th-century Dutch merchant Van Lindolan described Bengal as 'the granary of the east'.The Ganga and the Brahmaputra river systems have historically split the region into four broad divisions. Varendrabhumi, Rar or Radha Region, Central Bengal or Vanga, and Samatata
Varendrabhumi or Pundravardhana:
This includes the ancient Pundra Kingdom or Pundravardhana which developed in the later Vedic period.
The region is bounded by the Ganga and the Mahananda on the west, the Karatoya river on the east, the Padma on the south and the land between Koochbihar and the Terai on the north.
Traditionally, Bengali Brahmins are divided into two categories based on region, Rādhi, and Barendra.
Radha, Rar, or Rarh:
The expanse between the Chotanagpur plateau on the west and the Ganga river system on the East is known as Radha, Rar, or Rarh. Some historians believe that "Gangaridai", the name of an ancient Indian people in Greek literature, is a Greek corruption of "Ganga-Rāḍha".The place finds mentions in Mahavamsa and Dipavamsa, Buddhist chronicle of Srilanka.
Central Bengal or Vanga:
Greco-Roman chroniclers have mentioned the region as 'Gangaridai'. The ancient Vanga kingdom has been mentioned in Ramayana, Mahabharata. Sinhalese chronicles mention Vanga as the ancestral home of Prince Vijaya. Arthasastra of Kautilya recorded Vanga as an administrative unit. Kalidasa has described the kingdom as Naval power.
The region lay in between the Bhagirathi-Hooghly river system in the west and the Padma-Meghna river system in the east.
The historical region encompassed present-day Khulna, parts of the Barisal Division of Bangladesh.
In the west, it included parts of Burdwan, and Medinipur divisions and the whole Presidency Division of West Bengal
Chandraketugarh contains archaeological remains of the Vanga Kingdom.
Greek and Roman traders have mentioned this geopolitical division as 'Sonargaon'. Present-day Dhaka, Sylhet, Barisal, and Chittagon division of Bangladesh, Most of Tripura state of India and some part of Arakan region of Myanmar.
The account of Gupta ruler Samudra Gupta mentions 'Samatata' as a tributary state.
Buddhism flourished in the region before resurgent of Hinduism and later, Muslim conquest Bengal by Delhi Sultanate and Mughal empire.Mainamati in Comilla district of Bangladesh is an important buddhist archaeological site, it contains remains of Buddhhist archaeological sites from the period in between 6th and 12th century.