Townshend was the elder son of George Townshend, 16th Baron Ferrers of Chartley and 8th Baron Compton, by his wife Charlotte Ellerker. His father was the eldest son of George Townshend, 4th Viscount Townshend and was created Earl of Leicester in 1784, at which point Townshend adopted the courtesy title Lord Ferrers of Chartley. His grandfather was created Marquess Townshend in 1787, and his father inherited this title in 1807, at which point Townshend adopted the courtesy title Earl of Leicester. He succeeded his father as 3rd Marquess Townshend in 1811. Townshend was educated at Eton and Trinity College, Cambridge.
Marriage and scandal
In 1807, Leicester married Sarah, daughter and heiress of William Dunn Gardner. They had no children and Sarah left him only a year later, after accusing him both of being impotent and of having homosexual relations with his Italian secretary. She sued for annulment in the ecclesiastical courts, but very shortly afterwards, she eloped with another man. Thus, the marriage was never dissolved although she committed adultery by entering into a bigamous marriage. Following this scandal, Leicester was disinherited by his father for bringing disgrace to the family, and lived mainly abroad thereafter. In 1809, shortly after abandoning her husband, Sarah went through a ceremony of marriage with John Margetts, a brewer from St. Ives. The ceremony was held at Gretna Green. They had several children who bore their biological father's name until 1823. In that year, Sarah conveniently decided that the children should bear the surname of her legal husband, which they proceeded to do. The strictly legal position was that since Sarah's marriage had never been annulled, any children she bore would be deemed the progeny of her husband and ipso facto eligible to succeed him in his estates and titles. With this in mind, the eldest son John was baptised with the surname Townshend and assumed the courtesy title of "Earl of Leicester". He was later to represent Bodmin in the House of Commons. Alarmed at the pretensions of Sarah and her children, Townshend's younger brotherLord Charles Townshend petitioned in May 1842 to have Sarah's children delegitimated. Townshend supported the petition, and all the children were duly declared illegitimate by Act of Parliament in 1842. Sarah died on 11 September 1858. In 1843, after the Act of Parliament declaring him illegitimate was passed, the eldest son assumed his mother's maiden surname of Dunn Gardner.
Later years
Townshend died in Genoa in December 1855, aged 77. His only brother Charles, the petitioner in the legitimacy case, had predeceased him and left no sons either. Therefore, the Earldom of Leicester became extinct, while the baronies of Ferrers of Chartley and Compton fell into abeyance between his nephew and his youngest sister; it has remained in abeyance. He was succeeded in the Marquessate of Townshend by his first cousin, John Townshend.
