When the internal combustion engine took the place of the harness horses for private and commercial harness work and for breeding military horses, the growing interest in horse shows that offered worthwhile prizes in classes for harness horses offered Hackney breeders a new market. Show organizers saw these classes as a good public attraction and hackney horse classes became a feature at both large and small shows. High-stepping show Hackneys now became the sort breeders aimed for, most of them being amateurs who bred horses for their own pleasure. For the best results they became more selective in their choice of stallions but only a few stallions were found to be consistent producers of high action. These few attracted by far the greater number of mares. Regrettably, most of these stallions were of a smaller and finer-boned type. The high-stepping show horse became popular in the United States and some of the best British performers were sold to Americans for high prices. The result was that the breed really survived after the First World War as a specialist show horse and the judges at the breed show came to look upon extravagant action, even in hand classes for young stock, as the most desirable feature, details of conformation and temperament concerning them hardly at all.
Possibly to counter this trend and being aware that quite a number of light horses were still being used for commercial deliveries, about 1920 the British Ministry of agriculture published a handbook named British Breeds of Live Stock, and in it is the following description of the ideal Hackney horse:
The height as a rule is about 15 to 15.2 hands, but Hackneys are found to 16.2 or 16.3 occasionally. The general appearence shows compactness and strenght. The head should be neat and well formed, with a bright and intelligent eye and a pair of well set-up, alert-looking ears; it should be coupled easily and neatly to a long neck, clean and well defined at the throat and terminating, without any sign of weighting or lumpiness at the sides, in a pair of lean, deep and sloping shoulders. The junction of the neck and shoulders should be clearly marked, the shoulder points well defined and the withers fairly prominent but no to narrow. The back must be strong, the loins firm, the croup of good lenght, straight, and surmounted by a highly carried tail – a drooping croup and a low set tail are objectionable. The ribs should be deep, round and well sprung; the quarters deep and shapely. The forearms and thigs should be well clothed with muscle; the knees and hocks flat and large; the cannons short with plenty of hard flat bone; the pasterns nicely sloped and ending in a set of hard-wearing hoofs. From a front view the Hackney should be a big, bodly set-up horse having a big firm grip of the ground; well rounded of the ribs and strong and deep through the shoulders and breast, without beign too wide between the forelegs. Excessive width there is apt to make a horse go wide or in a rolling manner, though on the other hand a narrow chest imparts a weedy appearence and makes the horse liable to cut himself when moving. Viewed from behind, a typical Hackney is square with muscular thighs and gaskins and with no tendency to be “split up” between the legs (a bad fault); he should stand well on the ground with the hocks neither in nor out. The general appearence should give the impression of a bold, stylish animal eminently fitted to work in harness but also able to carry and keep a saddle in its proper position. Stallions should distinct masculinity al over, especially as regards their heads, crest development and general strenght.
The action of the Hackney is unique and most attractive. He should be a good square walker stepping well out and bearing himself juantily, but it is in the trot that he excels. He goes with both head and tail well up, the delivery in front is very free from the shoulder, the knee being raised from to some height with well rounded movement; the foot being moved forward and the whole leg almost straightened out before the foot regains the ground. The hocks are well and vigorously flexed, the hind feet are raised well off the ground and then brought sharply forward and replaced easily in a direct line with the fore ones. Viewed from the side, a good Hackney appears to be stepping well away in front and well under himself behind; in meeting you he should come with great resolution and without any suspicion of rolling, and in leaving you his action should be seen to be strong and true. Heavy plodding action is extremely objectionable, and is generally to be found accompanied by a low, heavy head carriage and crouching style.
In the author’s opinion, the Hackney Horse Society would be well advised to adopt this detailed description as a guide for breeders and judges with a view to preserving the breed as an excellent driving horse, well suited to modern requirements both for pleasure driving and for competition. Breeders should realise that breeding for a special show market can offer a worthwhile market only for a very few horses.
The Hackney Society has been controlled for the past eighty years almost entirely by those who only know the breed as a high-stepping show horse and despite a falling of in the general interest in the horse shows, the society’s council has never considered any changes that might meet the growing interest in pleasure driving and competition driving. Classes for young stock are still included in the programme for the annual breed show, but they are judged by one individual without any guidelines as to the judging procedure, or the standards of conformation and movement. Unfortunately, the entries no longer have to pass a veterinary examination. Most of the judges simply base their judgement on the stepping action of each horse at the trot even in the hand classes. A true four-beat walk is no longer regarded as of any importance …
… In the twenties and thirties of the last century there were still a few dedicated breeders in Britain who continued to breed Hackney horses of the old roadster type, notably Lord Ashtown, Mr. H. C Callaby, Mr. benjamin Oakes, Mr. Joseph Morton, and Mr. R. C. Monson.

Sir Augustus, the handsome head stallion at Lord Ashtown's stud at Woodlawn, County Galway, Ireland. One of his sons 8607 Protectionist (his mother was 837 Queen Mary 3), was registered in the Argentine Rural Society Stud Book, by Federico Martínez de Hoz, for his estancia El Araza in Castelli, Buenos Aires province.
Mr. Monson continued to breed quite a large number of horses during the 1920’s and early ’30s and some members of the Coaching Club bought horses from him. He also bred successful show horses from the same breeding stock. Both Lord Ashtown and Mr. Oakes wrote articles articles for the Livestock Journal and other periodicals with the aim of encouraging breeders in the preservation of the old type of Hackney. Sadly, the breed society gave them no real support in their efforts and today the Hackney horse is known to the rest of the horse world only as a show breed with excessive action and a difficult temperament.
South America (Argentina)
Export certificates were issued for forty-six stallions and forty seven mares to Buenos Aires in 1889, but these were al in the name of agents and the actual buyers’ names are not shown. It is likely that most were for wealthy estancia owners who lived for much of the year in Buenos Aires city and wanted good driving horses to use both in the city and on their extensive estancias in the country. They imported mostly horses of size ad substance with good roadster trotting action. Classes for Hackneys shown in hand were included in the International Exposition at Palermo from 1890, but these classes were only for mature stallions and mares. There were classes for horses shown in harness at some later expositions but these were judged as road horses with stylish, ground covering action rather than high-stepping show horses in light pneumatic-tyred single-seated wagons.
The largest stud of Hackneys in Argentina was the Chapadmalal Stud in Buenos Aires Province owned by Sr. Miguel Martínez de Hoz, who began breeding Hackneys about 1895. He imported both registered mares and stallions and in 1908 he brought forty-five young horses of Hackney breeding to England for use in a road coach service he intended to run through the summer from London to Guilford. The leading professional coachman of the day, Ted Fownes, was engaged to train the horses and he became the professional coachman for the Guilford run. Captain Geoffrey White, Royal Artillery, was the manager and he described the horses as having size, courage, and action of the right sort. Ted Fownes spoke of the four he drove on the mile stage from Cobbam into Guilford as “four lions”, which never took longer than fifty-five minutes to complete the stage. At the end of the season, the horses were sold by auction and were eagerly bought by the coaching fraternity.
The Hackney stud book records were kept by the Argentine Rural Society from 1907 (note by Raúl Aquerreta: The registry began with two Stud Books: a preliminar one and a definitive one. The Rural Society allowed in the first shows the competition between registered and not registered entries up to 1910 inclusive. Since 1911 to 1916 entries registered in both Stud Books: the preliminar and the definitive; and from 1916 only entries registered in the definitive Stud Book. Crosses with Thoroughbreds were never allowed) and only pure bred horses were registered. A small number of Hackney stallions were shipped to Buenos Aires after 1914, and the breeding of purebred horses of the old sort still continues on a somewhat reduced scale.