The Estrela Mountain Dog, known as the Cão da Serra da Estrela in its native Portugal, is one of the oldest and most esteemed breeds in the Iberian Peninsula. Originating from the remote, mountainous region of Serra da Estrela, this breed has been historically utilized as a guardian of livestock, particularly sheep and goats. The harsh terrain and the need to protect flocks from wolves and other predators contributed to the development of the Estrela Mountain Dog’s robust physique, keen intelligence, and fierce loyalty. Their lineage can be traced back several centuries, with references to similar dogs appearing in medieval texts and artwork. Throughout the centuries, the Estrela Mountain Dog remained relatively isolated in its homeland, allowing it to retain its original characteristics and traits. The breed was highly valued by shepherds and farmers not only for its guarding abilities but also for its adaptability to the rugged environment of the Serra da Estrela mountains. During the 19th and early 20th centuries, efforts were made to standardize the breed, leading to the establishment of breed standards and formal recognition. The first official breed standard was established in Portugal in the early 20th century, and the breed began to gain attention beyond its native region. In modern times, the Estrela Mountain Dog has transitioned from a purely working dog to a beloved companion and show dog, while still maintaining its traditional role in some rural areas. International recognition came in the mid-20th century when the breed was introduced to other countries, particularly in Europe and North America. Today, the Estrela Mountain Dog is admired for its gentle and protective nature, making it an excellent family pet and guardian. Despite its spread, efforts continue to preserve the breed’s heritage and ensure that it remains true to its origins as a steadfast protector of the flocks in the Serra da Estrela mountains.