The British Longhair cat is a semi-longhair version of British Shorthair. In the U.S. it is also referred to as the Lowlander. Apart from its fur, the British Longhair is identical to the British Shorthair.
This breed came about because the original longhaired British cat, because of interbreeding with imported longhairs, was developed into the Persian. This breed became increasingly massive and exaggerated with even longer, thicker fur than its earlier counterparts. Up until the 20th century, the Persian was considered the longhaired version of the British shorthair. During the 20th century, the Persian was interbred again, this time creating a shorthaired version, the Exotic Shorthair which would become its shorthaired equivalent. At this time, it was proposed that a longhaired British cat be reintroduced into the cat world, thus separating the British longhair and shorthair from the Persian and the Exotic Shorthair.