Sher Shah waged extensive wars with the Rajputs and expanded his empire. His conquests include Punjab, Malwa, Sind, Multan and Bundelkhand. His empire consisted of the whole of North India except Assam, Nepal, Kashmir and Gujarat.
Although his rule lasted for five years, he organized a brilliant administrative system. The central government consisted of several departments. The king was assisted by four important ministers:
Diwan -i- Wizarat - also called as Wazir - in charge of Revenue and Finance.
Diwan-i-Ariz - in charge of Army.
Diwan-i-Rasalat- Foreign Minister.
Diwan-i-Insha- Minister for Communications.
Sher Shah's empire was divided into forty seven sarkars. Chief Shiqdar (law and order) and Chief Munsif (judge) were the two officers in charge of the administration in each sarkar. Each sarkar was divided into several parganas. Shiqdar (military officer),Amin (land revenue), Fotedar (treasurer) Karkuns (accountants) were in charge of the administration of each pargana. There were also many administrative units called iqtas.
The land revenue administration was well organized under Sher Shah. Land survey was carefully done. All cultivable lands were classified into three classes - good, middle and bad. The state's share was one third of the average produce and it was paid in cash or crop. His revenue reforms increased the revenue of the state. Sher Shah introduced new silver coins called 'Dam' and they were in circulation till 1835.
Sher Shah had also improved the communications by laying four important highways. They were: 1. Sonargaon to Sind 2. Agra to Burhampur 3. Jodhpur to Chittor and 4. Lahore to Multan. Rest houses were built on the highways for the convenience of the travelers. Police was efficiently reorganized and crime was less during his regime.
The military administration was also efficiently reorganized and Sher Shah borrowed many ideas like the branding of horses from Alauddin Khalji.
Sher Shah remained a pious Muslim and generally tolerant towards other religions. He employed Hindus in important offices. He was also a patron of art and architecture. He built a new city on the banks of the river Yamuna near Delhi. Now the old fort called Purana Qila and its mosque is alone surviving. He also built a Mausoleum at Sasaram, which is considered as one of the master pieces of Indian architecture. Sher Shah also patronized the learned men. Malik Muhammad Jayasi wrote the famous Hindi work Padmavat during his reign.
After Sher Shah's death in 1545 his successors ruled till 1555 when Humayun reconquered India.