You do not have to believe what that intelligence-dwarf
@UKBengali says about Bengal of yesterday in Mughal time. However, Bengal was the richest Province of Hindustan.
How about then Punjab? Yes, it became a great agricultural land after the 1857 Sepoy Mutiny. Punjabis led by the Sikhs and followed by the Muslim Punjabis supported the British Indian govt to subdue the rebellion.
As a price, the British govt supported that region and its people with at least two things. One, they were recruited in the British Indian Army en mass. And the other is, the British govt started agriculture reforms thereby building many irrigation canals.
Punjab became very rich after this. Punjab soil is very fertile but it lacked water. So, with the introduction of an irrigation system throughout Punjab, the Province became very rich in agriculture after the 1860s.
But, before this, Bengal was the richest Province. Of the entire agricultural goods produced in Hindustan, about 1/3rd was produced in Bengal in terms of quantity. So, a huge amount of Mughal revenue was collected from this Province and spent in other Provinces. Bengal contributed more than any other Province of those days to the Mughals.
When I say Bengal, it is Bangladesh, west Bengal, Bihar, Jharkhand, a major part of Orissa, and a very little part of Assam. However, that dwarf-brained
@UKBengali thinks Bengal means only Bangladesh.