The Greek Shepherd or Greek Sheepdog (Greek: Ελληνικός Ποιμενικός, Ellinikós Pimenikós) is a breed of livestock guardian dog from Greece. Thought to be ancient in origin, the Greek Shepherd is very closely related to livestock guardian dog breeds from neighbouring countries; it is believed that some dogs are simultaneously claimed to be other breeds as they migrate annually across national borders with the flocks they protect in search seasonal pastures.