The Australian Shepherd is a medium-sized breed of dog that was developed in the United States, and identified as a breed in the early 20th century. The preceding forebears of the foundation dogs likely had several sources, but were primarily UK rural landrace herding collies of various types and/or regions. Other landrace types that oral histories commonly attribute to Australian Shepherd ancestry include herding farmcollies of the Iberian peninsula and German herding farmcollie types, with possible connections via travel to Australia prior to travel to the United States. (This last supposition is poorly supported by evidence, but is persistent in oral history traditions.) There is disagreement regarding the exact provenance of the breed's progenitures, prior to their arrival in the United States, and thus no official consensus on the origin of the breed name or association with Australia, or on exactly which landrace dogs contributed to the foundation dogs' gene pool.