The history of Kochi prior to the Portuguese is not well doccumented. Though places north and south of Kochi are mentioned in quite detail in many accounts by ancient travellers, even a mention of Kochi is absent prior to the arrival of the Portuguese. Kochi's prominence as a trading port grew after the collapse of the port at Kodungallur in 1341 AD.

The Cochin State came into existence in 1102 AD after the breaking up of the Kulasekhara empire The King of Kochi had authority over Cochin and adjoining areas. The Royal Family that ruled over Kochi was known as Perumpadappu Swaroopam. Till the end of the 12th century, the State was headquartered at the village of Perumpadappu. However, since the 18th century, mainland Kochi has remained the capital of the State

Portuguese period (1503 — 1663)
Mattancherry Palace-temple, which was built during Portuguese period by the Cochin Raja Veera Kerala VarmaKochi was the scene of the first European settlement in India . In the year 1500, Portuguese Admiral Pedro Álvares Cabral, landed at Cochin . The King of Kochi welcomed his guests and a treaty of friendship was signed. Promising his support in the conquest of Calicut , the admiral coaxed the king into allowing them to build a factory at Cochin . Assured by the support, the king called war with the Zamorins of Calicut . However the admiral retreated in panic on seeing the powers of the Zamorin . The Zamorins , on the other hand, eager to win the favor of the Portuguese, left without a war. Another captain, Joao Da Nova was sent in place of Cabral. However he too faltered at the sight of the Zamorin . The consecutive retreats made the King of Portugal indignant. The king sent Vasco Da Gama , who bombed Calicut and destroyed the Arab trading posts. This invited the anger of the Zamorin , who declared a war against the Kochi Raja.

Portuguese architecture of the Santa Cruz Cathedral Basilica in KochiThe war between Calicut and Cochin began on 1 March 1503. However, the oncoming monsoons and the arrival of a small Portuguese fleet under Francisco De Albuquerque alarmed the Zamorin , and he called back his army. The Zamorin resorted to a retreat also because the reverred festival of Onam was near, and the Zamorin intended to keep the auspicious day holy. This led to a triumph for the king of Kochi , who was later re-established in the possession of his kingdom. However, much of the kingdom was burnt and destroyed by the Zamorins.