His parents were English-born[1] Captain George Frederick Dashwood, a naval officer and public servant, and Sarah Rebecca née Loine.
He was educated at the Collegiate School of St Peter in Adelaide and later completed a year's study of civil engineering at the University of Ghent in Belgium.
[2] He then entered the legal profession, spending some time working as a clerk of courts before being admitted to the Bar in 1873.
The Northern Territory Times and Gazette praised his approach on more than one occasion, writing of him in 1896 as 'the personification of kindness in his dealing with aborigines'.
[1][5] After resigning from being Government Resident in January 1905, Dashwood continued to practise law, initially as the Crown Solicitor of South Australia before being appointed a King's Counsel in 1906.