It remained comparatively unaffected either by the Oriya immigration on the east, or by the later influx of Mahrattas on the west.
On the average in the province, before partition, out of every 1000 persons 528 spoke Bengali, 34 1 Hindi and Bihari, and 79 Oriya.
In October 1905 most of Sambalpur and five Oriya-speaking hill-states were transferred from the Central Provinces to Bengal, while the Hindi-speaking states of Chota Nagpur were transferred from Bengal to the Central Provinces.
The most important Aryan languages are Bengali, Bihari, Eastern Hindi and Oriya.
The province was reconstituted in 1905, when the Chittagong, Dacca and Rajshahi divisions, the district of Malda and the state of Hill Tippera were transferred from Bengal to a new province, Eastern Bengal and Assam; the five Hindi-speaking states of Chota Nagpur, namely Chang Bhakar, Korea, Sirguja, Udaipur and Jashpur, were transferred from Bengal to the Central Provinces; and Sambalpur and the five Oriya states of Bamra, Rairakhol, Sonpur, Patna and Kalahandi were transferred from the Central Provinces to Bengal.