A marquess or marquis ( /ˈmɑrkwɨs/; French: "marquis", /mɑrˈkiː/) is a nobleman of hereditary rank in various European peerages and in those of some of their former colonies. The term is also used to translate equivalent oriental styles, as in imperial China, Japan, and Vietnam (Annam). In the United Kingdom the title ranks below a duke and above an earl (see "Marquesses in the United Kingdom").

The actual distinction between a Marquess and other peerage titles has, in more recent years, faded into obscurity. In times past, the distinction between a Count and a marquess was that a marquess's land, called a march, was on the border of the country, while a count's land, called a county, often wasn't. Because of this, a marquess was trusted to defend and fortify against potentially hostile neighbors and was thus more important and ranked higher than a count. The title is ranked below duke, which was mostly restricted to the royal family and those that were held in high enough esteem to be granted such a title.

The word "marquess" is unusual in English, ending in "-ess" but referring to a male and not a female. In continental Europe it is usually equivalent where a cognate title exists. A woman with the rank of a marquess, or the wife of a marquess, is a marchioness (/ˌmɑrʃəˈnɛs/) in the United Kingdom, or a marquise (/mɑrˈkiːz/) elsewhere in Europe. The dignity, rank or position of the title is referred to as a marquisate or marquessate.

In the German lands, a Margrave was a ruler of an immediate Imperial territory (examples include the Margrave of Brandenburg, the Margrave of Baden and the Margrave of Bayreuth) and never a mere noble like Marquesses/Marquises in Western and Southern Europe. German rulers did not confer the title of Marquis and holders of marquisates in Central Europe were mostly of Italian and Spanish origin.

Read more about Marquess:  Etymology, Marquesal Titles in Other European Languages, Equivalent Non-Western Titles