||This article needs additional citations for verification. (May
2009)| |Count / Earl| A duke (male) or duchess (female) can
either be a monarch ruling over a duchy or a member of the
nobility, historically of highest rank below the monarch. 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. During the Middle Ages the title
signified first among the Germanic monarchies. Dukes were the
rulers of the provinces and the superiors of the counts in the
cities and later, in the feudal monarchies, the highest-ranking
peers of the king. A duke may or may not be, ipso facto, a
member of the nation's peerage: in the United Kingdom and Spain
all dukes are/were also peers of the realm, in France some were
and some were not, while the term is not applicable to dukedoms
of other nations, even where a