The decisive battle of the third Carnatic War was fought at Wandiwash on 22 January 1760.
General Eyre Coote’s army totally routed the French army under Lally. In the next three months all the minor French possessions in the Carnatic had been effectively reduced by Coote’s efforts.
The French were left with no possessions in the Carnatic except Jinje and Pondicherry. Finally, in May 1760, the English laid siege to Pondicherry.
At this juncture Lally tried to retrieve the situation with a last ditch attempt at alliance with Nawab Haidar Ali of Mysore.
The latter even sent a contingent to the aid of the French. But the French and Haidar Ali’s contingent were unable to decide on a concerted plan of action and Haidar’s contingent ultimately returned to Mysore without fighting a single battle.
After more than six months of encirclement, the French capital of Pondicherry unconditionally surrendered on 16 January, 1761.
The city was completely destroyed by the victors and its fortifications reduced to mere rubble. A contemporary account states that “in a few months not a roof was left standing in this once fair and flourishing city”.
Shortly thereafter Jinje and Mahe, the two French settlements on the Malabar Coast also surrendered to the English leaving the French without even a toehold in India.
More distressing was the fate of the French general Count de Lally. After being detained as an English prisoner of war for two years, he was allowed to return to France at the end of the Seven Years War, but far from receiving kind treatment; he was imprisoned in the Bastille for more than two years and afterwards executed.