The important characteristics of the Vijayanagar administration was the Amara-Nayaka system. The top-grade officers of the army were known as Nayaks or Palaiyagars or Poligars. These officers were granted land in lieu of their services.
Khwaja Abu Malik Isami is the author of Futuh-al-Salatin is yet another elaborate account of the Delhi Sultanate. It consists of almost 12,000 verses. The Futuh-us-Salatin is a history of Muslim rule in India until 1349-50.
The Tabaqat-i-Nasiri which was compiled in 1260 CE by the author Minhaj-i-Siraj and it gives a complete account of Muhammad of Ghur’s conquest of India and the history of the Delhi Sultanate up to 1260 CE.