Hyder Ali, after a march across the country, which he marked by fire and sword, suddenly turned upon Arcot, and on the 21st of August 1780 sat down before that city, as the first operation of the war. Arcot was the capital town of the territory of the nabob of that name, the only prince in India who was friendly and in alliance with the Company. It contained immense stores of provisions, and, what was equally wanted, a vast treasure of money. There was another important reason, which required on the part of the British an immediate attention to this movement. Lieut.-Colonel Baillie, with a body of troops, was in the Northern Circars; and Hyder Ali, by besieging Arcot, had interposed himself between this detachment and the main army under Major-General Sir Hector Munro. Orders were immediately sent to Lieut.-Colonel Baillie to hasten to the Mount, to join the main army; and Sir Hector Munro, at once to meet Lieut.-Colonel Baillie and to raise the siege of Arcot, marched on the 25th of August with his army for Conjeveram, a place forty miles distant from Madras, in the Arcot road.
The British troops were followed during the whole way by the enemy’s horse. They were four days on their march to Conjeveram, and when they arrived, they found the whole country under water, and no provisions of any kind to be procured. So relax were the commissaries appointed by the Madras government, that the army had but four days’ provisions; in the midst of the most fertile region of India, and in the very onset and commencement of a war, the troops were in danger of being famished. The army had no other resource than to spread itself individually over the fields, and, at the risk of being destroyed in detail by the enemy’s horse, collect the growing rice, up to their knees in water.
Hyder Ali, as the British general foresaw, raised the siege of Arcot upon this movement towards Conjeveram; but, what he had not foreseen, his politic enemy threw his army in such a manner across the only possible road of Lieut.-Colonel Baillie’s detachment, as to prevent the desired junction, which had been expected to have taken place on the 30th of August, the day after the arrival of the army at Conjeveram. Lieut.-Colonel Baillie, before this last movement of the enemy to cut him off, had been stopped for some days, at no great distance, by the sudden rising of a small river. Hyder made use of this time to throw his army between them. On the 5th of September Lieut.-Colonel Baillie effected his passage over the river, but Hyder, being informed of it, made a second movement, which completely intercepted him. In order in some degree, however, to defeat this movement, but with slight hopes of success, Sir Hector Munro changed his position likewise, and advanced about two miles, to a high ground on the Tripassoor road, which was the way that the expected detachment was to come. By these movements the hostile camps were brought within two miles of each other, the enemy lying about that distance to the left of the British.