Diwan the connotaion of the word diwan has undergone much changes in the history of the Muslim rulers. Umar, the second khalifah of Islam first introduced the diwan. He made an elaborate system of granting pension to the Muslims. The pension roll and the office for this pensionary account was called the diwan. In the sultanate period of Delhi, the diwan stood for a department of administration, much the same as the present ministry, for example the diwan-i-wazarat (the department of wazir), diwan-i-Arz (military department in charge of recruitment and payment of salaries) etc.
In the Mughal period, the term diwan stood for a person, the head of the revenue department, and the office was known as diwani; the head of the branches of the revenue department was also known as diwan, for example, Diwan-i-tan. The head of the revenue department of the subahs or provinces was also known as diwan. During the time of akbar the diwan of provinces was made independent of the subahdar (head of administration), still later, the provincial government was divided into nizamat (general administration) and diwani (revenue department). In Bengal murshid quli khan was the last great and important diwan appointed by the last great Mughal emperor aurangzeb. Murshid Quli Khan united both the offices of nazim and diwan under him, and this position continued upto the end of the Muslim rule. [Abdul Karim]
Bibliography PK Hitti, History of the Arabs, 4th edition revised, 1949; A Karim, Murshid Quli Khan and His Times, Dhaka, 1963; IH Qurashi, Administration of the Sultanate of Delhi, 5th edition, 1971.