Bull-type terriers are a dog sub-type of terriers. It is also a section of the terrier group at the Fédération Cynologique Internationale (FCI). All bull-type terriers share the same ancestry in the crossbreeding between bulldog breeds and terriers.
Blood sports, once extremely popular, became illegal in England in 1835, but continued to be secretly practiced. Sports such as rat-baiting and dog fighting had grown in popularity because it was easier to hide such events compared to bull-baiting. For dog fighting, the best dogs in these sports (Old English Bulldogs and terriers) were crossbred to produce the bull and terrier, a type with varied appearance but selected for strong fighting traits. This was the common ancestor of the modern breeds that are part of the bull-type terrier group.