He entered the Royal Naval College, Dartmouth in 1819 and served 1832–1833 under Captain C. H. Fremantle on HMS Challenger, noted for earlier (1829) claiming all of New Holland west of New South Wales for the Crown.
[1] Dashwood married Sarah Rebecca Loine on 27 December 1839 in a Catholic church in London.
He purchased an estate 5 miles (8.0 km) west of Meadows, named Dashwood's Gully.
[2] In 1842 he was appointed justice of the peace and sworn in as magistrate, and on 15 June 1843 he was appointed to the Legislative Council, holding this position until July 1844,[4] when he resigned, and apart from a public meeting at which he protested against the proposed settlement in the colony of a contingent of Parkhurst boys,[5] he took no part in public life until November 1846, when he was reappointed J.P., and in April 1847 he was made Acting Commissioner of Police and Police Magistrate.
In July 1858 he was appointed Emigration Agent in Great Britain, and apart from a visit in May 1861 was in England until late 1862, when the office was abolished,[7] and served as Stipendiary Magistrate in various places including Mount Barker and Strathalbyn.