The Field Spaniel was developed in England in the latter half of the 19th century to be a medium-sized, all-black dog, which was unusual at the time as most hunters preferred dogs with some white so they could be easily seen in the field. The Field Spaniel was created at the same time that dog shows were becoming popular and is considered the first spaniel developed for conformation showing while at the same time retaining his excellent skills in the field.
Until 1901, spaniels were divided by weight, so if one puppy in a litter grew to be more than 25 pounds, he was called a Field Spaniel. If he weighed less than 25 pounds, he was classified as a Cocker Spaniel.
The breed started out as a popular dog, but through some not-so-successful cross-breeding, fanciers turned him into a dog that was longer than he was tall, with short legs, a large head, and too much coat. In the late 1800s and early 1900s, there was a mix iof Sussex, Cocker and even Irish Water Spaniels in the breeding. That didn't make for a very good or very attractive hunting dog, and the public expressed its displeasure. Through the efforts of dedicated lovers of the Field Spaniel and the introduction of the English Springer Spaniel the breed began to return to the original type envisioned by the original developers of the breed.
Field Spaniels nearly became extinct during World War 2. Thankfully due to the efforts of breeders at the time, the breed survived. Interestingly, all modern Field Spaniels descend directly from two dogs and two bitches from the late 1960s.