The term "Bandog" in medieval Britain was not a specific breed but a descriptive term for a type of large, powerful working dog, typically a Mastiff or similar molosser-type dog, which was kept chained or "banded" during the day and released at night to guard property. 

History and Usage

Origin of the Term: The word "bandogge" originated around 1250–1300 in Middle England and is thought to derive from the Old Saxon word "banda" (chain) and "doc" (dog), literally meaning "chained dog". This highlights their primary management method rather than their genetic lineage.

Physical Description: Historical accounts describe them as "huge dogs, stubborn, uglier, eager, burthenouse of bodie, terrible and fearful to behold". They were selected for their strength, stamina, confidence, and fearlessness.

Primary Roles:

Guarding and Protection: Their main use was to guard and protect homesteads, farms, and properties from intruders and poachers at night.

Hunting: They were employed for hunting large game, such as wild boar and even for locating poachers.

Baiting: In later medieval and early modern periods (around the 16th century), they were also used in blood sports like bull-baiting and bear-baiting.

Other Tasks: Dr. Johannes Caius mentioned in 1576 that they were "serviceable against the fox and the badger, to drive wild and tame swine out of meadows, and pastures". 

Ancestry and Legacy

The original medieval Bandogs were working dogs of various crosses and sizes, without a unified breed standard. They typically descended from eastern shepherds and mastiffs crossed with western Bullenbeissers and hounds. 

The "old bandog" is now very rare ,even though the concept of creating a superior protection dog was revived in the 1960s by an American veterinarian, John Swinford, who aimed to recreate the functional medieval working mastiff. Modern "Bandogs" are typically crosses of specific breeds, such as American Pit Bull Terriers and Neapolitan Mastiffs or English Mastiffs, bred for guarding purposes.