Thomas Arthur , comte de Lally Thomas Arthur , comte de Lally , baron de Tollendal ( January 1702 – 6 May 1766 ) was a French General of Irish Jacobite Gallowglass ancestry . He commanded French forces in India during the Seven Years War . After a failed attempt to capture Madras he lost the Battle of Wandiwash to British forces under Eyre Coote and then was forced to surrender the remaining French post at Pondicherry . After a time spent as a prisoner of war in Britain , Lally returned to France where he was executed as a punishment for his failures in India . Life . He was born at Romans - sur - Isère , Dauphiné , the son of Sir Gerald Lally , an Irish Jacobite from Tuam , County Galway , who married a French lady of noble family , from whom the son inherited his titles . Entering the French army in 1721 he served in the war of 1734 against Austria ; he was present at Dettingen ( 1743 ) , and commanded the " regiment de Lally " in the famous Irish brigade at Fontenoy ( May 1745 ) . He was made a brigadier on the field by Louis XV . He had previously been mixed up in several Jacobite plots , and in 1745 accompanied Charles Edward to Scotland , serving as " aide - de - camp " at the battle of Falkirk ( January 1746 ) . Escaping to France , he served with Marshal Saxe in the Low Countries , and at the capture of Maastricht ( 1748 ) was made a " maréchal de camp " . When war broke out with Britain in 1756 Lally was given the command of a French expedition to India . He reached Pondicherry in April 1758 , and at the outset met with some trifling military success . He was a man of courage and a capable general ; but his pride and ferocity made him disliked by his officers and hated by his soldiers , while he regarded the natives as slaves , despised their assistance , and trampled on their traditions of caste . In consequence everything went wrong with him . He was unsuccessful in an attack on Tanjore , and had to retire from the Siege of Madras ( 1758 ) owing to the timely arrival of the British fleet . He was defeated by Sir Eyre Coote at the Battle of Wandiwash ( 1760 ) , and besieged in Pondicherry , where he was forced to capitulate in 1761 . Execution . Lally was sent as a prisoner of war to England . While in London , he heard that he was accused in France of treason , and insisted , against advice , on returning on parole to stand his trial . He was kept prisoner for nearly two years before the trial began ; then , after many painful delays , he was sentenced to death on May 6 , 1766 , and three days later beheaded . Louis XV tried to throw the responsibility for what was undoubtedly a judicial murder on his ministers and the public , but his policy needed a scapegoat , and he was probably well content not to exercise his authority to save an almost friendless foreigner . In volume one of his " French Revolution " , Thomas Carlyle describes the death of Lally as a judicial murder , reporting that Lally was driven to execution gagged to prevent his crying out against the injustice , and that when Lally ' s son came of age , he sought to have his father ' s name cleared in the Parlement de Paris . The orator Despreminil acted as spokesman of Parlement and refused to consider any repentance , much to his discredit in Carlyle ' s opinion . See GB Malleson , " The Career of Count Lally " ( 1865 ) ; " Z ' s " ( the marquis de Lally - Tollendal ) article in the " Biographie Michaud " ; and Voltaire ' s " Œuvres complètes " . The legal documents are preserved in the " Bibliothèque Nationale " .