Mysore (/maɪˈsʊər/), officially renamed as Mysuru, is the third largest city in terms of population in the state of Karnataka, India, which served as the capital city of Mysore Princely Kingdom (Kingdom of Mysore) for nearly six centuries, from 1399 until 1947.ysore is connected by National Highway NH-212 to the state border town of Gundlupet, where the road forks into the states of Kerala and Tamil Nadu. State Highway 17, which connects Mysore to Bangalore, was upgraded to a four-lane highway in 2006, reducing travel time between the two cities.