Why Madras was renamed Chennai?

On 17 July 1996, nearly five decades after India's independence, the DMK government of Tamil Nadu renamed the city of Madras to Chennai, following the national trend of using less anglicized names. The name Madras was thought to have Portuguese origins after a Portuguese higher authority named Madre de Sois, who was among the early settlers in the region along the Coromandel Coast in the 1500s.

Another explanation is that Madras was an abbreviation for Madraspatnam, the site chosen by the East India Company for a permanent settlement in 1639. While the British did not incorporate Chennapatnam, a small town to its south around the fort. Chennapatnam is the origin of the name Chennai. The space between northern Madraspatnam and southern Chennapatnam was built over so quickly that the two villages essentially became one town. The newly united town was known as Madraspatnam by the British, but Chennapatnam by the Indians. The precise original locations of Madraspatnam and Chennapatnam became mixed up over time. Madras was considered the fort site, while Chennapatnam was considered the north Indian town. The British preferred the name Madras, while the locals called it Chennapatnam or Chennapuri. Chenna is a Dravidian name that appears to be derived from the Telugu word Chennu, which means "beautiful." There is also speculation that Madras is a Tamil origin name, whereas Chennai is not.