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.
Under the rule of the Vijayanagar empire, irrigation became prominent. The development of irrigation took place mainly during the rule of Deva Raya I. New tanks were built and dams were constructed across the river Tungabhadra.