Diwani-i-WIzarat:It was the finance department headed by the wazir (Prime-minister). Naib wazir acted as deputy to wazir. The wazir was assisted by the mushrif-i-mamalik, (accountant) who maintained a record of the accounts and the mustauf-i-mamalik (auditor) who audited this account. Under Firuz Tughluq, wazirs became hereditary.
Diwan-i-Ariz: Headed by the Ariz-i-mamalik, it was the ministry of defence. He was responsible for organization and maintenance of the royal army. The review of the army and branding of the horses was done by Ariz-i-mamalik.
Diwan-i-Insha: The department of correspondence and records of the royal court was held under the charge of a central minister known as dabir-i-mamalik, dabir-i-khas or amir- munshi. The dabir-i-mamalik acted as private secretary of the Sultan and drafted firmans. He was assisted by dabirs (clerks).
Diwan-i-Risalat:Under the period of the slave dynasty, the head of the public charities and ecclesiastical department was the sadr-us-sudur. In his capacity as rasul of the Sultan, he received appeals and complaints from public and redressed their grievances.
