A rock inscription dating from the reign of Emperor Ashoka, who ruled India in the 200's B.C., refers to the Chera people. It is probably the first historical mention of Kerala as a distinct region of India. The region was ruled by the Chera dynasty until the A.D. 400's.
Traders from as far away as Rome brought gold coins and took away pepper. During this period, Hinduism, Buddhism, and Jainism were introduced to South India by monks and migrants.

St. Thomas, the Christian apostle, is traditionally said to have founded the "Syrian" Church at Muziris (Cranganore) before A.D. 100. Jewish migrants established a settlement in Cochin in the 900's. After the decline of the Chera dynasty, 200 years of confusion followed.
During this time, Islam was introduced into Kerala by Arab merchants, whose descendants are locally known as Moplahs. In 825, the Kulasekhara dynasty began a new calendar, founded the city of Quilon, and set Kerala on a new path to greatness. Over the next 200 years, Malayalam developed as a separate language, which was close to, but distinct from, Tamil. Arts and learning flourished.

A hundred years of conflict with the Chola dynasty of what is now Tamil Nadu destroyed Kerala's prosperity and split it into small, warring states. Ravi Varma Kulasekhara, a local ruler, established a short-lived empire, uniting Kerala. His sudden death in 1314 caused Kerala to fall apart once more into small, mutually hostile areas.

In 1498, the Portuguese explorer Vasco da Gama landed at Calicut, and on Dec. 25, 1500, the Portuguese navigator Pedro Alvares Cabral arrived and began the Portuguese dominance of trade on the Malabar coast. The Dutch pushed out the Portuguese in the 1600's but were themselves decisively crushed in 1741 by King Martanda Varma of Travancore. Martanda Varma unified Travancore under his control. Between 1766 and 1790, the region was devastated by invasions from Mysore led by Hyder Ali and Tipu Sultan.

After the death of Tipu Sultan in 1792, the East India Company of Britain annexed Malabar. A series of treaties brought the states of Travancore and Cochin also under their control. British control of Kerala was punctuated by rebellions. Pazhassi Raja of Malabar led a five-year revolt against British rule which ended with his death in 1805. Another uprising, under Velu Thampi of Travancore, also ended with the death of its leader in 1809. The Moplahs rose in rebellion from 1849 to 1855, and again in 1921.

The positive aspects of British rule included the establishment of an education system and the extension of plantation agriculture, especially tea. They improved Cochin as a major port and set up a network of communications, including better links with the rest of India. These links became the basis of development after India gained its independence in 1947.

The move toward democracy in Kerala was first expressed through social reforms. The most influential reformer was Narayana Guru, whose slogan was "One caste, one religion, one God for mankind." The Communists played an important part in the anticolonial movement in Kerala. Prominent among them were K. P. Kesava Menon, A. K. Pillai, E. M. S. Namboodiripad, K. Kesavan, T. M. Varghese, P. Krishna Pillai, and A. K. Gopalan.
In 1947, the Communists organized armed insurrections against the state of Travancore in the villages of Vayalar and Punnapra.
In 1949, the two separate states of Travancore and Cochin were united. In 1956, the boundaries of the newly united states were revised to include neighbouring Malayalam-speaking areas, and the whole territory was officially named Kerala.