Conditionally both breeds are ranked as "straight-haired sheepdogs" but, like all other ancient breeds, each of them is something much more than a breed in the generally known interpretation of the word. This means that there is still much misunderstanding and confusion about their "kinship". Originally the definition of the breed was not based on the exterior, but on the working qualities of the dog, so the phenotype could change considerably over the centuries. It was not until the mid-twentieth century that it became firmly established (to be sure of this, it is worth looking at photos, reports from exhibitions in the early twentieth century).

Today there are hypotheses claiming kinship between corgis and various breeds. As a rule, they are based solely on visual similarities. For example, there is an opinion that the Cardigan is a distant relative of dachshund dogs, but when it got the infusion from this branch, when it moved away from it, remains only a guess.

Most likely, the lineage of the humble four-legged aborigines of western Britain traces back to the very time when they arrived here accompanied by the first humans. It is not their fault that this lineage has been lost to the ages. Over the course of thousands of years, the Corgi may have crossed with different breeds of dogs that were brought to the British Isles. At this point there is no way to either disprove or prove the theories that arise on the subject.