Guide to British Noble Titles

Today it was announced that newlyweds Prince William and Kate Middleton will officially be known as the duke and duchess of Cambridge. But what, exactly, does that mean -- not to mention how do you decipher who's who on the royal wedding guest list? Find out, with the help of our a handy guide to British royal titles:

King: Male ruler of a kingdom.

Queen: Female ruler of a kingdom.

Prince: Ruler of a principality, which is a sovereign state; the title is granted (and can be revoked) by the sovereign.

Princess: A title generally held by either the daughters of a British sovereign, the male-line granddaughters of a British sovereign or the wife of a British prince.

Duke: A member of the nobility, historically of highest rank below the monarch, and historically controlling a duchy, which is a specific territory.

Duchess: The wife of a duke. (However, Camilla Parker Bowles is known as a duchess, a choice she made to avoid confusion with Prince Charles' first wife, Princess Diana.)

Marquess: A member of the nobility, traditionally a rank below duke. Though now obsolete, the distinction between an earl and a marquess used to be that a marquess' land, called a march, was on the border of the country, while an earl's land, called a county, often wasn't. A woman with the rank of marquess, or the wife of a marquess, is a marchioness.

Earl: A member of the nobility who ranks below a marquess and above viscount. In the 5th and 6th centuries, an earl collected fines and taxes and in return was entitled to a third of the money collected. Present day titleholders take their names from towns, mountains or surnames.

Viscount: A member of the nobility who ranks below an earl. The title originally referred to a person who served as a deputy or lieutenant of a count, or the sheriff of a county. Current titleholders usually take their name from a place, a surname or a combination of both.

Lord, Lady: Generally, any noble member except a duke or duchess is referred to as a lord (male) or lady (female) as are the children, former wives and other close relatives of the nobility.

Master: At one time used for men of rank, it now primarily is used for boys generally younger than 13 in formal correspondence, particularly invitations to formal events.

Sir: The formal reference for a knight and used with the full name, but not with the surname alone ("Sir Elton John," but not "Sir John"). A knighthood today recognizes significant contributions to national life and includes such people as actors, scientists, school leaders and industrialists. The female equivalent is a dame.

Susie Castillo T.A.T.u. Talisa Soto