Duke

Duke is a male title either of a monarch ruling over a duchy, or of a member of royalty, or nobility. As rulers, dukes are ranked below emperors, kings, grand princes, grand dukes, and sovereign princes. As royalty or nobility, they are ranked below princess nobility and grand dukes. The title comes from French duc, itself from the Latin dux, 'leader', a term used in republican Rome to refer to a military commander without an official rank (particularly one of Germanic or Celtic origin), and later coming to mean the leading military commander of a province. In most countries, the word duchess is the female equivalent. Following the reforms of the emperor Diocletian (which separated the civilian and military administrations of the Roman provinces), a dux became the military commander in each province. The title dux, Hellenised to doux, survived in the Eastern Roman Empire where it continu...