The 16th was one of the battalions left to garrison the town and to assist in dismantling the defences.
1780: Defence of Permacoil Fort.
In September, 1780, Hyder Ali, the Sultan of Mysore, invaded the Carnatic in alliance with the French. The Battalion, less one company under Lieutenant Bishop at Permacoil Fort, joined the main army which marched to Conjeeveram, with the object of joining hands with a detachment under Colonel Baillie, which was marching from Guntoor.
Defeat of Colonel Baillie’s Detachment.
This detachment was attacked by Hyder Ali within eight miles of the main army. Sir Hector Munro sent a force, consisting of the flank companies of the army, to rescue Colonel Baillie, but the entire detachment was either killed or taken prisoner to Seringapatam. The army, thus reduced, was forced to retire to Madras, with the loss of baggage, being harassed the whole way by the Mysore Cavalry. Sir Hector Munro was relieved of his command for not having supported Colonel Baillie with his whole army instead of with a detachment only. Sir Eyre Coote took over command and formed the army into three divisions, the Battalion being placed in the 2nd (or Left) Division under Colonel Lord MacLeod.
1781: “Carnatic”.
Arrangements having been made for the supply of the army, it marched from The Mount on January 17th, strength 7,450 (including 1,600 Europeans) and 62 guns.
Relief of Permacoil.
The first object was the relief of various forts besieged by Hyder Ali, among them Permacoil, held by one company of the 16th. This was effected. Lieutenant Bishop was noted for immediate promotion for the gallant manner in which he had carried out the defence, but this was disallowed by the Directors of the Company as contrary to the established custom.