Under the patronage of his uncle William Menelaus, he was articled with a firm of solicitors in Birmingham, before entering the Inner Temple as a student in 1872.

[1] After unsuccessfully contesting Hackney South as a Conservative in 1885 and 1886, Darling was returned for Deptford in a by-election in 1888, defeating Wilfrid Scawen Blunt, and held the seat until his elevation to the bench in 1897.

[1] Assigned to the Queen's Bench Division, Darling presided over a number of important trials, including the Stinie Morrison case (1911),[2] that of "Chicago May",[3] and the trial for criminal libel of Noel Pemberton Billing MP (1918), brought by Maud Allan after Billing and Harold Sherwood Spencer had claimed there were 47,000 "sexual perverts" in high places who were controlled by the Germans.

He was known for his erudition and at times inappropriate wit,[1] both on and off the bench, as well as for being impeccably dressed and wearing a silk top hat whilst riding to Court on a horse and accompanied by a liveried groom.

'[5] During the Billing trial one of the witnesses, Eileen Villiers-Stuart, claimed to have seen the mysterious "Black Book" in which the names of the "perverts" were listed, declared in court that Darling was one of them.

As the Senior Puisne Judge in the King's Bench Division, Darling deputized for him, and was sworn of the Privy Council in 1917 as a reward.

Darling went so far as to write to Hewart asking for the office "even for ten minutes", but was passed over in favour of Mr Justice A. T. Lawrence.