As with its cousin Irish Terrier, there is almost no written evidence of the exact genesis of the Kerry Blue Terrier before 1800, which means that its past is shrouded in secrets.
Legend has it that the ancestor of the Kerrys swam to the Irish coast from a ship that sank in Tralee Bay at the end of 1700. Elsewhere, however, it is claimed that the Kerry Blue Terrier is descended from the dogs that reached the coast of Ireland alive after the shipwreck of the Spanish Armada in 1588.
There is agreement, however, that the surviving shipwrecked person (s) is assumed to have been paired with local terriers, from which the dark blue fur is firmly associated with the type and nature of the terrier.
In the same context there are also references to "blackish blue" terriers, which are said to have originated in County Kerry and other areas, from which it was concluded that the ominous "shipwrecked" had found his partner here, so that the blue color of the fur originated.
Another suggestion is that the Kerry Blue Terrier is a relative of the Irish Wolfhound. If the rather improbable story with the surviving "shipwrecked" should correspond to the facts, the question still arises in this case, what kind of dog it was. 

It could either have been one of the shaggy German Shepherd types that brought the longer coat with the fading pigmentation and herding properties to the native terriers, or it was a water dog of the type which was also the ancestor of the poodle, water spaniel and Portuguese water dog who was responsible for the water ability, the ruffled coat and the gray factor of the Kerry Blue Terrier.
In any case, it is certain that the Kerry Blue Terrier was used in Ireland in the 18th century as a guard and herding dog as well as a hunting and fighting dog. He guarded the scattered courtyards, kept mice and rats short and drove the cattle.
In addition, it was a popular sport in Ireland until the 19th century to let dogs fight either against the dangerous badgers or against each other, whereby the strong and large terriers were able to distinguish themselves.
Although the Kerry Blue Terrier was used for all terrier jobs, it was said to be the "only terrier that can take on an otter in deep water by itself".
Over time, one or the other portion of Bedlington and Dandie Dinmont Terrier blood has surely flowed into the breed, but he is still referred to as the “real blue native” of the Emerald Isle.

There it reached its heyday around 1920, when four Irish clubs looked after it at the same time. Two years later it was shown for the first time in England and in 1924 the American Kennel Club officially recognized it as a separate breed.
In the same year, over 25% of the Irish Kennel Club's entries were Kerry Blue Terrier! At that time the fight for Irish national independence against England was already in full swing and the Kerry Blue Terrier became the mascot of the Irish patriots.
Despite these difficult times, the Dublin Blue Terrier Club was founded in 1920 by people who, as Irish republicans or loyal unionists, were politically hostile, but put these differences aside as soon as it came to dogs.
According to the history of the breed, the first show of this group took place under the approval and care of the British Kennel Club. Judge Dan Nolan, however, was on the wanted list of the British government as a member of the Irish Republican Army (IRA).
Although members of the English Kennel Club and the inspector of the local police were among the contestants and spectators, Judge Dan Nolan was not arrested because they preferred to compete for the Wyndham Quinn Challenge Cup for the best Kerry Blue Terrier .
American enthusiasts first exhibited the breed at Westminster Castle in 1923. The exhibitors included the wife of the American press magnate, Mrs. William Randolph Hearst, and the then heavyweight boxing world champion, Gene Tunney.