British Shorthairs are believed to have descended from ordinary domestic cats living in ancient Rome. They arrived in what is now Great Britain thanks to Roman legionaries who invaded the islands 2,000 years ago. They brought them to combat rodents that were destroying food supplies in military warehouses. For centuries, these cats lived in English cities and on farms as "farm animals," valued primarily for their hunting skills. By fighting and breeding among themselves, through natural selection, they developed, over generations, the traits that are so desirable in them today - a muscular, compact body and broad shoulders, short, strong legs, and short, extremely dense fur, thanks to which they could withstand various weather conditions. Over time, people also began to notice the valuable qualities of their "inner" nature – loyalty, unobtrusive sociability, and a calm, trusting disposition.

The islanders' interest in breeding and improving their own lines of pedigree cats flourished during the Victorian era of the nineteenth century. Paradoxically, this was fueled by the presence of cat breeds arriving from the Orient. The proud Britons decided to define their own local breed as a counterweight to the exotic arrivals from distant lands. The creator of the British Shorthair breed standard is considered to be Harrison Weir, an English illustrator and nature painter who, according to some sources, personally selected and bred the best individuals from among the English "backyard cats." In 1871, Weir organized the first cat exhibition at the Crystal Palace in London, at which British Shorthairs were the only cats exhibited as pedigree cats.....all others were shown as "ordinary" longhairs or "ordinary" shorthairs, divided into various colors. The first-ever Best In Show award was given to a fourteen-year-old British Shorthair blue tabby cat.
British Shorthairs dominated the annual Crystal Palace cat shows until the early 20th century, when breeders' preferences changed and longhaired cats began to dominate the shows. An attempt to save the British Shorthair's position was the establishment of the first-ever Shorthaired Cat Society in 1901, whose statutory goals included the promotion of shorthaired cats, and British Shorthairs in particular.
World War I brought the first major crisis in the breeding and development of cat breeds, including the British Shorthair. The lack of good representatives of the breed among registered pedigree cats forced breeders to turn to their non-pedigree, domestic cousins for reproduction. The results of these efforts, however, were unsatisfactory, as the type and conformation of the offspring from such matings differed from those achieved before the war. Another method of rebuilding the breed was to cross British Shorthairs with Persians. The results were better, but in both cases, the kittens from such unions could not be registered as purebred. They had to be recrossed with purebred British Shorthairs for three generations before they could be registered as pedigree British Shorthairs. These problems, combined with the growing popularity of Persians and other purebred shorthairs, meant that the British Shorthair's status steadily declined. In the 1930s, Kit Wilson, a feline judge and avid animal lover, became interested in the breed. Thanks to her and other enthusiasts' dedication, the British Shorthair cat breed survived the Great Depression and World War II, but the number of truly valuable British cats was severely limited. Furthermore, most of them were related to each other, which resulted in a weak genetic makeup. To ensure greater genetic diversity, domestic shorthair cats were once again used, as well as other shorthaired pedigree cat breeds—Russian Blues, Burmese, and Carthusians. Such efforts strengthened the cats' health and immunity, but had a negative impact on their build—causing the British Shorthairs to take on "Oriental" characteristics—becoming slimmer and more delicate.