[1] From offering minor political advice to the monarch as amatya (Sanskrit for minister) like in the Vijayanagara Empire to later acting as a major military chieftain as dalvoy[2] (Kannada for military chief) like in other southern kingdoms to being the head of the government as dewan (Persian/Urdu for accountant or chief adviser) like in the Ottoman Empire, the role has transmuted in powers over time.
Owing to the deposition of Maharaja Krishnaraja Wadiyar II by his own dalvoy Hyder Ali and his assumption as the supreme leader in 1761, until after Ali's son Tipu was briefly in that position, the role of dalvoy became abandoned.
[3] After Ali's death in 1782, Tipu assumed absolute over Mysore and officially created the office of the Dewan of Mysore when he made his longtime childhood friend and his father's aide K. Purnaiah his adviser and a military strategist.
Tipu considerably de-recognised the maharajas and the role of dewan was gradually ever more codified into government.
After Tipu's death in 1799, British India installed Krishnaraja Wadiyar III as the maharaja.