Warren, Richard Augustus (1705–75), Jacobite and French army officer, was born at Corduff near Castleknock, Co. Dublin, son of John Warren and Mary Warren (née Jones). Two of his brothers became officers in the Irish brigade in the service of France, while a third became a Franciscan priest and a sister became a nun at Montreuil, France. Compelled by financial distress to emigrate, he and his younger brothers and sister moved to France, where Richard worked as a merchant at Marseilles. However, it was clear that his inclination was for a military career and in 1744 he became a volunteer captain, without pay, in the French army. Attaching himself to Col. Rothe's Irish regiment he fought at the battle of Fontenoy (11 May 1745) and became a committed supporter of the Jacobite cause. In October 1745 he landed at Stonehaven in Scotland to serve in the army of Prince Charles, the Pretender. At Perth he assisted in the construction of batteries to drive off warships; his efficiency and strong character made a deep impression on Charles, who gave him the rank of colonel (which was also conferred on him by King Louis upon his return to France), while Lord George Murray appointed him his ADC. Warren fought at the siege of Carlisle and later returned to France to seek reinforcements. In 1746 he embarked on a secret mission to Scotland to rescue the Young Pretender, having volunteered despite the great danger. During this adventure he arrested a highland chief, MacDonald, who had turned traitor. The mission was a success and on his return to France a grateful James III, then in Rome, made Warren a knight baronet for ‘gallant service’; however he was only allowed to use this title publicly after 1751. In 1747 he returned to the army at Flanders and became ADC to Marshal Saxe, serving with great distinction until the peace of 1748. In 1750 he was made ‘brigadier general of the English troops’ as a reward for his loyalty to the Jacobite cause.
On the outbreak of the Seven Years' War in 1756 he was appointed brigadier of infantry in the French army and was given command of a number of Irish regiments. Money was always in short supply for Warren. In 1759 he pleaded unsuccessfully for a peerage from James III so that he could embark on a lucrative marriage. As a reward for his diplomatic work at Belleisle, in negotiating with the English, the French government appointed him governor of the fortress and the neighbouring islands. In 1762 he became a maréchal-de-camp and soon after a French subject. After contracting a terminal illness he died in 1775. He was unmarried and his financial recklessness meant that he died in debt. An idealistic man with scholarly interests, Warren was always willing to risk everything for the restoration of the Stuart monarchy – the guiding principle of his life.