Bengal become autonomous state in first half of 18th century, copying the trend of regional autonomy in various Mughal Subas, but till then sovereignty of the Mughal emperor was not challenged, the establishment of all offices within the region to govern showed the emergence of an independent focus of authority in Bengal. The authority was set up and followed by many famous rulers such as:
i. Murshid Kuli Khan:
After death of Aurangzeb, Murshid Kuli Khan established an independent state of Bengal but he did not defy the imperial authority till then his administration indicated the establishment of dynastic rule in Bengal, thereby doing away with the selection of Nawab by the emperor. He combined the office of Nazim and Diwan by abolishing its separation to strengthen the power of Governor. He took new measures to increase the revenue collection in Bengal like:
i. Eliminate the small intermediary Zamindars.
ii. Expel rebellious Zamindars and Jagirdars to the frontier provinces of Orissa.
iii. Enlarge the Khalsa lands.
iv. Enlarge the Zamindari who assumed responsibility of revenue collection and payment.
Thus, the new power structure, now emerged was very different from Mughal model.
ii. Shujauddin and Bengal:
Sarfaraz was deposed by his father Shujauddin Muhammad Khan. He always pay tribute to Mughal court, but managed the affairs in his own way He imitated the system of administration of Murshid
Kuli Khan and tries to develop ties of loyalty with local power groups and also forced Philip B. to comment to help by cooperation of the dominant force of Bengal. The changing power equation was best demonstrated in couple of 1739 and 1740 by Alvardi Ali Khan who killed Sarfaraz Khan to seized power.
iii. Alvardi Khan and Bengal:
Alvardi Khan obtained imperial confirmation of his position like his predecessors, but showed the signs of break away with Mughal rule. He made major appointment to enforce his authority. He appointed large number of Hindus as revenue administrators. He reduced ties with imperical control in Delhi without formally defying the imperial authority.
There were two great threats for Bengal at that time one is Maratha and another is Afghan, but Alvardi tried his best to solve the problem and to stop the loss of property in wars. He started to give chauth of 1,200,000 and ceding Orissa to Mustafa Khan, the Afghan general. He got his Patna back by him, but it was great financial loss for Bengal and effected it in future.