 He was admitted to the NSW Bar on 2 June 1862 and was later appointed a Queens Counsel (QC) in 1878.Biographer Percival Serle states that Darley had established a good practice, and that for the twenty years preceding his elevation to the bench, there was hardly an important case at Sydney in which he did not appear on one side or the other.Biographer John Bennett, on the other hand, states that Darley found his early years tiring and not particularly well remunerated, and that it was Darley's zeal rather than his legal skills that brought him to attention.