Duke
Greater公爵 · Duke — The Highest Noble, Second Only to the King
The duke is the highest title in the European feudal noble system, the highest noble rank below royalty (kings and princes). The etymology comes from Latin 'dux' (military commander), a military position in late Rome referring to supreme commanders of frontier armies. After Germanic settlement, it evolved into hereditary lords governing entire tribes or vast regions. Under 9th-century Charlemagne, the Frankish empire's five great duchies (Saxony, Bavaria, Swabia, Franconia, Lotharingia) were formed, sharing power with the emperor. A duchy was the size of a small kingdom containing multiple counties and marquessates, maintaining its own army, courts, and currency. The most famous duchies include England's Duke of Normandy (later the English royal house), France's Duke of Burgundy, and Italy's Duke of Milan. In modern Britain, it remains the highest non-royal title, with the Duke of Westminster and Duke of Marlborough still active. Titles: 'Duke,' wife 'Duchess.'