Chennai, also known as Madras, is the capital and largest city of Tamil Nadu, the southernmost state of India. It is located on the Coromandel Coast of the Bay of Bengal. As per the 2011 Indian census, Chennai is the sixth-most-populous city in India and forms the fourth-most-populous urban agglomeration. The city is coterminous with Chennai district, which together with the adjoining suburbs constitutes the Chennai Metropolitan Area, one of the largest metropolitan areas of India. It is administered by the Greater Chennai Corporation, which was incorporated in 1688, and is the second oldest municipal corporation in the world after the City of London Corporation. Being the capital of the state, it houses major government institutions including the Tamil Nadu Legislative Assembly, and the Madras High Court.
Archeological evidence points to human settlements in the region during the Stone Age. Historically, from the 1st century CE, the region was part of the Chola, Pallava, Pandya, and Vijayanagara kingdoms during various eras. In 1639, the British East India Company obtained a grant for a strip of coastal land which then contained the fishing village of Madrasapattinam. The British developed the Madras port and built Fort St. George, the first British fortress in India. The British were engaged in conflict with the French for the control of the city in the 18th century. By the late 18th century, the British had conquered most of the region and established the Madras Presidency with Madras as the capital. After India gained independence in 1947, Madras became the capital city of the Madras State, the predecessor to the present-day state of Tamil Nadu. The city was officially renamed as Chennai in 1996.
Chennai lies on the predominantly flat Eastern Coastal Plains, and experiences a tropical climate with high humidity. It receives most of the rainfall from the Northeast monsoon with cyclones being common features during the season, resulting in water inundation and flooding in low-lying areas. As of 2024, Chennai had an estimated GDP of $196.5 billion, ranking it among the most productive metro areas in India. It has a diversified industrial base anchored by different sectors, and is amongst the top export districts in the country, with more than US$2.563 billion in exports. It is ranked as a beta-level city in the Global Cities Index, and houses a major portion of India's automobile industry. The city has a well developed infrastructure, and is a major transportation hub. It is a major centre for medical tourism and is termed "India's health capital". It was ranked as the second-safest city in India by the National Crime Records Bureau in 2023.
Chennai is home to a diverse population of ethno-religious communities, with a majority Hindu population (80.7%). The city houses a migrant population of nearly three million and has the third-largest expatriate population in India. Known as the gateway to South India, it is amongst the most-visited Indian cities by international tourists and was ranked 36th among the most-visited cities in the world in 2019 by Euromonitor. Tamil is the most widely spoken language, with Madras Bashai being a unique linguistic variation of Tamil spoken by people in the city. Chennai is a major centre for music, art and dance and is called the Cultural Capital of South India. The oldest buildings in the city date from the 6th to 8th centuries CE, and the city has buildings encompassing diverse styles of architecture developed during different time periods in history. It is a major film production centre and home to the Tamil-language film industry. In October 2017, Chennai was added to the UNESCO Creative Cities Network (UCCN) list.
The name Chennai was derived from the name of Chennappa Nayaka, a Nayak ruler who served as a general under Venkata Raya of the Vijayanagara Empire from whom the British East India Company took the town in lease in 1639. The first official use of the name was in August 1639 in a sale deed to Francis Day of the East India Company. A land grant was given to the Chennakesava Perumal Temple in Chennapatanam later in 1646, which some scholars argue to be the first use of the name.
The name Madras is of native origin, and has been shown to have been in use before the British established a presence in India. A Vijayanagara-era inscription found in 2015 was dated to the year 1367 and mentions the port of Mādarasanpattanam, along with other small ports on the east coast, and it was theorized that the aforementioned port is the fishing port of Royapuram. Madras might have been derived from Madraspattinam, a fishing village north of Fort St. George.
In July 1996, the Government of Tamil Nadu officially changed the name from Madras to Chennai. The name "Madras" continues to be used occasionally for the city as well as for places or things named after the city in the past.
Stone Age implements have been found near Pallavaram in Chennai, and according to the Archaeological Survey of India, Pallavaram was a megalithic cultural establishment, with evidence of pre-historic settlements. The region around Chennai was an important administrative, military, and economic centre for many centuries. During the 1st century CE, Tamil poet Thiruvalluvar lived in the town of Mylapore, a neighbourhood of present-day Chennai. In the 2nd century CE, the region was part of Tondaimandalam ruled by the Early Cholas, who subdued the Kurumbas, the original inhabitants of the region. The Pallavas of Kanchi became the independent rulers of the region from 3rd to 9th century CE, and the areas of Mahabalipuram and Pallavaram were developed during the reign of Pallava king Mahendravarman I. In 879 CE, the Pallavas were defeated by the Later Cholas led by Aditya I. Jatavarman Sundara Pandyan later brought the region under the Pandya rule in 1264 CE. The region came under the influence of the Vijayanagara Empire in the 15th century CE.
The Portuguese arrived in 1522 CE and built the port of São Tomé, named after the Christian apostle St. Thomas, who is believed to have preached in the area between 52 and 70 CE. In 1612, the Dutch established themselves near Pulicat to the north of Chennai. On 20 August 1639, Francis Day of the British East India Company, along with the Chennapa Nayaka, the Nayak of Kalahasti, met with the Vijayanagara emperor Peda Venkata Raya at Chandragiri and requested a grant for land on the Coromandel coast on which the company would build a factory and warehouse for their trading activities. On 22 August 1639, a grant was given for a strip of land about 9.7 km (6 mi) long and 1.6 km (1 mi) inland for an annual sum of fifty million pagodas. The land was then part of a fishing village known as Madraspatnam. A year later, the Company built Fort St. George, the first major English settlement in India, which became the nucleus of the growing colonial city of Madras.
In 1746, during the Battle of Madras, the city along with the Fort St. George, was captured and plundered by the French under the command of General La Bourdonnais, then Governor of Mauritius. The British regained control in 1749 CE through the Treaty of Aix-la-Chapelle. The town's fortress wall was strengthened to withstand further attacks from the French and Hyder Ali of the Kingdom of Mysore. The British resisted a French siege attempt in 1759. In 1769, the city was threatened by Hyder Ali during the First Anglo-Mysore War and the Treaty of Madras later ended the conflict. By the 18th century CE, the British had conquered most of the region and established the Madras Presidency with Madras as the capital.
Madras became a major naval base and the central administrative centre for the British in South India. The city was the baseline for the Great Trigonometrical Survey of India, which was started on 10 April 1802. With the advent of railways in India in the 19th century, the city was connected to other major cities such as Bombay and Calcutta, promoting increased communication and trade with the hinterland.