In subsequent decades Docker held directorships of the Midland Bank, and of four major railway companies in the Midlands, London and the South East.
In 1918 his machinations were behind the formation of Wagon Repairs, Ltd., another successful conglomerate, dedicated, 'in the UK or elsewhere, to repairing, rebuilding, reconstruction, painting, altering, converting, equipping, adapting, making fit for traffic, supplying and dealing with railway and other wagons, trucks, corves, carriages, trolleys, trolleys, vans and vehicles, and repairing wheels, axles and components.'
In 1921 he formed the Electric and Railway Finance Corporation. Famed as a 'fixer' putting together mergers and business deals, Docker was a founder of the Midlands Employers Federation in 1913, and in 1914 bought a London evening newspaper, The Globe, to agitate for greater influence of industrialists in government policy towards business.
He was founder President in 1916 of the Federation of British Industries, which he intended to act as a ‘business parliament’ supplanting the responsibilities of the Westminster parliament in commercial, fiscal, and labour matters; indeed as a master of persuasion, Dudley Docker's unique energies were largely responsible for the subsequent creation of the future Confederation of British Industry, the CBI.
In the 1880s Docker played several games of county cricket for Midland counties. He served on the committee of newly founded Warwickshire County Cricket Club until 1892, having been the highest scoring batsman at the inaugural match of the Edgbaston ground in June 1886 (when he was voted man of the match); he also playing for his county against Australia the same summer, and against the 'Gentlemen of Canada' the following year.
He was a keen shot, and usually spent time in Scotland each year, where he enjoyed fast walking on the moors, and was a member of the Royal Thames Yacht Squadron.
He was made a Commander of the Bath in 1911, largely because of his energies in recruiting troops (many of them from the Saltley Works) for the Territorial Army. In 1929 he was offered a Barony; but regrettably the offer was withdrawn by the government due to resentment in the city, partly because of his role in the purchase by the International General Electric Company of a major interest in Metropolitan-Vickers Electrical Company, which attracted much criticism from some of his colleagues.
Docker's perceptive biographer, Richard Davenport-Hines, to whom much of this article is indebted (see picture of his excellent book Dudley Docker: Life of a Trade Warrior, above), in the DNB interestingly sums up Dudley Docker's appearance, character and outlook thus:
'He was tall and well built, with a big nose. As a young man he seemed jovial and frank, although he could be intimidating: his small, intense, unblinking eyes quelled dissidence. He was always mercenary, and had an unbeatable understanding of other mercenary men. He disliked others being in authority over him, and resented politicians or officials whom he could not bribe or browbeat.
'In business he was always bold, flexible, persuasive, ruthless, and opportunistic; from 1918 onwards he might be judged unscrupulous. At committee meetings Docker was taciturn and even inarticulate, but he was so shrewd and calculating that he was often able to direct deliberations by informal pressure. Increasingly he liked to operate through nominees, and was usually a good delegator. He had a retentive memory, and an acuity in financial affairs that was hard to surpass.
'The least gullible of men, some of his political enthusiasms were nevertheless unrealistic. Apparently he suffered from nervous strains which made him increasingly pessimistic and aggressive; he may have developed claustrophobia, and about 1916 came to dislike crowded meetings or public attention. Latterly he was secretive.'
Dudley Docker died of angina and tonsillitis in July 1944, at his home, Coleshill House, near Amersham, Buckinghamshire, and was buried at Coleshill in north Warwickshire.
An Irish racehorse, a bay gelding owned by a Mr. Joshua Pearce, bears the name 'Dudley Docker'; and at the University of Birmingham a number of Dudley Docker research scholarships in Engineering and Engineering Science are awarded regularly.