Original: By the 18th century two breeds had been developed for hunting hare and rabbit: the Southern Hound and the North Country Beagle (or Northern Hound). The Southern Hound, a tall, heavy dog with a square head, and long, soft ears, was common from south of the River Trent and probably closely related to the Talbot Hound.
Simplified: They are extinct now, but once they had made the Southern Hound more popular, which helped the Southern Hound descend to the Beagle.