Invasion of Kerala (1763-1792) was initiated by Hyder Ali. Hyder Ali marched to Kerala in 1757 as king of Palghat who was a military victim of his neighbour ruler of Calicut (Zamorin) requested him to do so. Hyder Ali supported by Palghat troops marched into Southern Malabar and defeated Calicut King. Zamorin paid 12 hundred thousand as security to Hyder Ali and the army was withdrawn.

Again in 1766, he marched to Kerala and waged a futile struggle to subdue Malabar. He occupied kingdoms of Chirakkal, Kottayam, Kadathanad, Calicut, Walluvanad and Palghat. King of Cochin accepted his supremacy and paid him an annual tribute till 1790. Hyder Ali attempted to capture Travancore in 1767 but failed. Tipu Sultan also tried to possess it towards the end of eighteenth century but was unsuccessful. Travancore was only part of Kerala that was not under the purview of Kingdom of Mysore.

When the King of Cannanore came to know about the news of Hyder`s conquest of Bednur in 1763, he requested Hyder to invade Kerala and help him fight with his enemy Chirakkal Raja of Kolathiri. Hyder defeated the Kolathiri Raja. Thereafter he captured the kingdom of Kottayam. The army of Hyder Ali faced tough opposition from Kadathanad but managed to occupy it. Then he marched to Calicut and kept Zamorin under house arrest as he was unable to pay him the sum that he had agreed to pay in 1757. Zamorin could not face the atrocities anymore and committed self immolation.

Sultan Bathery derives its present name from Tipu Sultan of Mysore who used the abandoned Jain temple here and used it as his battery hence the name Sultan`s Battery. Hyder Ali`s army suffered a defeat in the hands of Kottayam Nairs in Northern Malabar. In the following year the Mysore forces retreated from Malabar to Coimbatore, and crushed the uprising, and commanded to build the strategic Palakkad Fort.

Most of Nair kings got their kingdoms back through meaningful negotiations with the king of Mysore. A couple of years later, Kolathunad was also given to Kolathiri by some negotiations.

In 1773, Mysore forces lead by Said Saheb and Srinivasarao marched to Malabar through the Thamarassery Pass and occupied territories directly. Hyder tried to invade Travancore in1774 as he saw the economical background of the Kingdom of Travancore. He moved southwards and reached Travancore in 1776.

Hyder Ali asked the kings of Cochin and of Travancore, to compensate him for his Malabar campaign. King of Cochin paid the sum however King of Travancore replied in negative and stated that if Hyder Ali withdrew from Malabar with his forces and reinstated the local Rajas back in their kingdoms, he will provide some money. Mysore army began to move to Travancore from the north. In 1776, Northern frontiers of Cochin were invaded and the fort at Trichur was also captured. Then Hyder advanced to Travancore Defence Lines.

Invasions by Tipu Sultan
In 1787, Tipu Sultan captured Iruvazhinadu, by killing Kurungothu Nair, the ruler of Iruvazhinadu who was a French ally. Alliances changed on the Malabar Coast. Arakkal Beebi moved to the English and Kolathiri replaced them as the ally of Mysore. It was his dream to capture Travancore. Tipu Sultan tried to induce Travancore tactically with the help of Kingdom of Cochin

Battle of the Nedumkotta (Travancore-Mysore War)
In the month of December 1789 Tipu Sultan attacked the Nedumkotta from north. However Tipu was forced to retreat due to the British attack on Mysore.

Fall of Calicut
In 1789, Tipu Sultan marched to Kozhikode and destroyed the fort. He destroyed several temples of Kozhikode too.

End of Mysore Rule
The Treaty of Seringapatam signed in 1792; Malabar was surrendered to the English East India Company. This resulted in a sharp limitation of Mysore`s borders to the advantage of the Mahrattas, the Nizam of Hyderabad and the Madras Presidency. The districts of Malabar, Salem, Bellary and Anantapur were surrendered to the Madras Presidency.