Digby was elected to the House of Commons for Ludgershall in 1755, a seat he held until 1761, and then represented Wells between 1761 and 1765. From 1763 to 1765, he was a Lord of the Admiralty.[2] In 1757 he succeeded his elder brother Edward as the 7th Baron Digby but as this was an Irish peerage it did not entitle him to sit in the British House of Lords and did not force him to resign his seat in the House of Commons. It did however give him ownership of the family seat of Sherborne Castle.[3][4]
In 1765 Digby was created Baron Digby, of Sherborne in the County of Dorset, in the Peerage of Great Britain with remainder to the male issue of his father. He had then to give up his seat in the Commons and join his peers in the Lords. From 1771 to 1793 Lord Digby served as Lord Lieutenant of Dorset.[5]
In 1790 he was further honoured when he was Viscount Coleshill and Earl Digby in the Peerage of Great Britain, with remainder to his heirs male.[6]
Hon. Edward Digby (1764–1764), who died in infancy.[5]
After his first wife's death in 1765 he married, secondly, Mary Knowler, daughter of John Knowler Recorder of Canterbury, on 10 November 1770.[8] They had five children:[5]
Hon. Henry Digby (1774–1776), who died in infancy.[5]
Hon. Rev. Robert Digby (1775–1830), the rector of Sheldon and vicar of Coleshill.[5]
Hon. Stephen Digby (1776–1795), who died young.[5]
Lord Digby died in September 1793, aged 62, and was succeeded in his title by his eldest son Edward. Countess Digby died in 1794.[5] As his eldest son died unmarried and without issue in 1856, the viscountcy and earldom became extinct and the barony passed to his cousin, Edward St Vincent Digby.[1]
