Kochi formerly known as Cochin) is a city in the Indian state of Kerala. The city is one of the principal seaports of the country and is located in the district of Ernakulam, about 220 kilometres (140 mi) north of the state capital, Thiruvananthapuram. It has an estimated population of 600,000, with an extended metropolitan population of about 1.5 million, making it the largest urban agglomeration and the second largest city in Kerala after the capital.

Since 1102 CE, Kochi was the seat of the Kingdom of Cochin, a princely state which traces its lineage to the Kulasekhara empire. Heralded as the Queen of the Arabian Sea, Kochi was an important spice trading centre on the Arabian Sea coast from the 14th century onwards. Ancient travellers and tradesmen referred to Kochi in their writings, variously alluding to it as Cocym, Cochym, Cochin, and Cochi. Occupied by the Portuguese in 1503, Kochi was the site of the first European colonial settlement in India. It remained the capital of Portuguese India until 1530, when Goa became the capital. The city was later occupied by the Dutch, the Mysore and the British. Kochi was the first princely state to willingly join the Indian Union, when India gained independence in 1947.

Kochi experienced decades of economic stagnation from independence until 2003, when it entered a period of economic growth, leading to a spurt in the city's development. A growing centre of information technology, tourism and international trade, Kochi is the commercial hub of Kerala, and one of the fastest growing second-tier metros in India. Like other large cities in the developing world, Kochi continues to struggle with urbanisation problems such as substandard sanitation and traffic congestion.

Successive waves of migration over the course of several millennia have made Kochi a cultural melting pot. Despite the risk of overdevelopment, the city retains its distinct colonial heritage and a blend of tradition and modernity.

Kochi was the centre of Indian spice trade for many centuries, and was known to the Yavanas (Greeks) as well as Romans, Jews, Arabs, and Chinese since ancient times.Kochi rose to significance as a trading centre after the port at Kodungallur (Cranganore) was destroyed by massive flooding of the river Periyar in 1341. The earliest documented references to Kochi occur in books written by Chinese voyager Ma Huan during his visit to Kochi in the 15th century as part of Admiral Zheng He's treasure fleet. There are also references to Kochi in accounts written by Italian traveller Niccolò Da Conti, who visited Kochi in 1440.

The Kingdom of Kochi came into existence in 1102, after the fall of the Kulasekhara empire. The King of Kochi had authority over the region encompassing the present city of Kochi and adjoining areas. The reign was hereditary, and the family that ruled over Kochi was known as the Cochin Royal Family (Perumpadappu Swaroopam in the local vernacular). The mainland Kochi remained the capital of the princely state since the 18th century. However, during much of this time, the kingdom was under foreign rule, and the King often only had titular privileges.

Fort Kochi in Kochi was the first European colonial settlement in India. From 1503 to 1663, Fort Kochi was ruled by Portugal. This Portuguese period was difficult for the Jews installed in the region, since the Inquisition was active in Portuguese India. Kochi hosted the grave of Vasco da Gama, the first European explorer to set sail for India, who was buried at St. Francis Church until his remains were returned to Portugal in 1539. The Portuguese rule was followed by that of the Dutch, who had allied with the Zamorins in order to conquer Kochi. By 1773, the Mysore King Hyder Ali extended his conquest in the Malabar region to Kochi forcing it to become a tributary of Mysore. The hereditary Prime Ministership of Kochi held by the Paliath Achans came to an end during this period.

Meanwhile, the Dutch, fearing an outbreak of war on the United Provinces signed a treaty with the United Kingdom, under which Kochi was ceded to the United Kingdom in exchange for the island of Bangka. However, there are evidences of English habitation in the region even prior to the signing of the treaty. In 1866, Fort Kochi became a municipality, and its first Municipal Council election was conducted in 1883. The Maharaja of Cochin, who ruled under the British, in 1896 initiated local administration by forming town councils in Mattancherry and Ernakulam. In 1925, Kochi legislative assembly was constituted due to public pressure on the state.

Towards the early 20th century, trade at the port had increased substantially, and the need to develop the port was greatly felt. Harbour engineer Robert Bristow was brought to Kochi in 1920 under the direction of Lord Willingdon, then the Governor of Madras. In a span of 21 years, he transformed Kochi as one of the safest harbours in the peninsula, where ships berthed alongside the newly reclaimed inner harbour equipped with a long array of steam cranes.

In 1947, India gained independence from the British colonial rule. Cochin was the first princely state to join the Indian Union willingly. In 1949, Travancore-Cochin state came into being with the merger of Cochin and Travancore. The King of Travancore was the Rajpramukh of the Travancore-Cochin Union from 1949 to 1956. Travancore-Cochin, was in turn merged with the Malabar district of the Madras State. Finally, the Government of India's States Reorganisation Act (1956) inaugurated a new state — Kerala — incorporating Travancore-Cochin (excluding the four southern Taluks which were merged with Tamil Nadu), Malabar District, and the taluk of Kasargod, South Kanara. On 9 July 1960, the Mattancherry council passed a resolution—which was forwarded to the government—requesting the formation of a municipal corporation by combining the existing municipalities of Fort Kochi, Mattancherry, and Ernakulam. The government appointed a commission to study the feasibility of the suggested merger. Based on its report, the Kerala Legislative Assembly approved the corporation's formation. On 1 November 1967, exactly eleven years since the establishment of the state of Kerala, the corporation of Cochin came into existence. The merger leading to the establishment of the corporation, was between the municipalities of Ernakulam, Mattancherry and Fort Kochi, along with that of the Willingdon Island, four panchayats (Palluruthy, Vennala, Vyttila and Edappally), and the small islands of Gundu and Ramanthuruth.

Kochi witnessed economic stagnation in the years following India's independence. The city's economic recovery gathered momentum after economic reforms in India introduced by the central government in the mid-1990s. Since 2000, the service sector has revitalised the city’s stagnant economy. Over the years, the city has witnessed rapid commercialisation, and has today grown into the commercial capital of Kerala.

Schools and colleges in the city are either run by the government or by private trusts and individuals. The schools are each affiliated with either the Indian Certificate of Secondary Education (ICSE), the Central Board for Secondary Education (CBSE), or the Kerala State Education Board. English is the medium of instruction in most private schools; though government run schools offer both English and Malayalam. After completing their secondary education, which involves ten years of schooling, students typically enrol at Higher Secondary School in one of the three streams—Arts, Commerce or Science. Upon completing the required coursework, the student can enroll in general or professional degree programmes.

The Cochin University is situated in the city. Most of the colleges offering tertiary education are affiliated either with the Mahatma Gandhi University or the Cochin University. Other national educational institutes include the Central Institute of Fisheries Nautical and Engineering Training, the National University of Advanced Legal Studies, the National Institute of Oceanography and the Central Marine Fisheries Research Institute.