His wealth and his friendship with Lord Caledon enabled him to sit in Parliament for various boroughs until 1818, although he was not a particularly conspicuous member.
Born about 1761, Josias was the third son of Paul Porcher, a planter of Charleston, South Carolina, and his wife Esther Du Pré.
[1] Porcher returned home in 1796, bearing a diamond sword presented by the nawab of Arcot to the Prince of Wales.
In the same year, he also brokered the purchase of the burgages of Old Sarum from Camelford by Du Pre Alexander, 2nd Earl of Caledon.
He married, on 1 Nov. 1787 at Fort George, Madras, Charlotte, the daughter of Admiral Sir William Burnaby, 1st Baronet, of Broughton Hall, Oxfordshire.