The Duchy of Savoy was a historical state located in the western Alps, primarily in what is now Italy and France. Established in the 11th century, it became a significant political entity in Europe, known for its strategic location and influence over trade routes. The duchy played a crucial role in the formation of modern states in the region. In the 15th century, the Duchy of Savoy expanded its territory and power, eventually becoming part of the Kingdom of Sardinia in the 18th century. The duchy was ruled by the House of Savoy, which later became the royal family of unified Italy in the 19th century.