Explanation:

Vijanagar Empire:

It covered most of the present day South India.
It was established by Hakka and Bukka under the guidance of Sage Vidyaranya mainly for the purpose of protecting Hinduism from Muslim invaders.
About 5 Muslim kingdoms came together against Vijayanagara Empire at the Battle of Talikota and barely won against Vijayanagara Empire. This shows the military power of the mighty Vijayanagara empire. FOR MORE INFORMATION ABOUT THE BATTLE visit Battle of Talikota - Wikipedia.
Over 7000 inscriptions have been found belonging to Vijayanagara Empire. They are in various languages such as Kannada, Telugu, Tamil etc.
King Krishnadevaraya's personal army consisted of 100,000 infantry, 20,000 cavalrymen and over 900 elephants. This number was only a part of the army numbering over 1.1 million soldiers, a figure that varied as an army of two million has also been recorded along with the existence of a navy as evidenced by the use of the term Navigadaprabhu (commander of the navy)