The Battle of Colachel was fought on 10 August 1741 between the Indian kingdom of Travancore and the Dutch East India Company, during the Travancore-Dutch War.
In the early 18th century, the Malabar Coast region of present-day Kerala was divided among several small chiefdoms. In the 1730s, Marthanda Varma, the ruler of Travancore, adopted an expansionist policy, and conquered several territories from these small states. Also, he refused to honour the monopoly contracts that the Dutch had with those states annexted by Travancore. This step adversely impacted the spice trade and other commercial interests of Dutch.
This threatened the interests of the Dutch East India Company’s command at Malabar, whose spice trade depended on procurement of spices from these states. Marthanda Varma and his vassals refused to honour the monopoly contracts that the Dutch had with the states annexed by Travancore, adversely affecting the Dutch trade in Malabar.
Dutch tried for bilateral negotitions which was not accepted by Marthanda Varma. This lead to the battle.
On 26 November, the Dutch sent two large ships and three sloops to Colachel , bombarding the coast. Marthanda Varma sent 2,000 soldiers of Nair Brigade to Colachel.The war continued for a while and on 5 August, a cannonball fired by the Travancore army fell into a barrel of gunpowder inside the Dutch garrison, and the resulting fire destroyed the entire rice supply of the stockade. Consequently, the Dutch were forced to surrender on 7 August.
It was the first time in Indian history that an Asian country defeated a European naval force. The Dutch never recovered from the defeat and no longer posed a large colonial threat to India.
Eustachius De Lannoy who was captured in the battle, subsequently earned the trust of the king, Maharaja Marthanda Varma, who made him an officer in the Travancore military. De Lannoy trained the Travancore army on European lines and, in the course of time, became a valiant and successful commander of the very same foreign army that had defeated his Dutch forces.
At some point of his military career, De Lannoy got well acquainted with Neelakanta Pillai, a Nair palace official, who after learning of Christian traditions and beliefs through De Lannoy, converted to Christianity. As they both had influential roles under the king, they got well acquainted. Neelankanta Pillai took the baptised name of Devasahayam Pillai. Devasahayam became a martyr of the Christian faith in 1752.