A duchy, also called a dukedom, is a country, territory, fief, or domain ruled by a duke or duchess. In Western European tradition, the title of duke ranked among the highest nobility, generally just below the monarch and above counts or earls.
Historically, there was a significant distinction between sovereign dukes, who ruled independent states, and dukes who were simply noblemen within larger kingdoms. Some duchies functioned as sovereign states in regions that only later became unified nation‑states, such as Germany (once the Holy Roman Empire, a federal empire) and Italy (later a unified kingdom). By contrast, other duchies were subordinate territories within kingdoms that had already consolidated, either partially or fully, during the medieval era: examples include France, Spain, Sicily, Naples, and the Papal States.
