British aristocracy

 or peerage, comprises, in descending order, the ranks duke, marquess, earl/countess, viscount, and baron/ baroness. Male peers below the rank of duke may be referred to as Lord (i.e., the Earl of Avon may be called Lord Avon), and all peeresses may be referred to as Lady. However, not every lord is a peer. The eldest son of a duke, marquess, or earl, for instance, may use one of his father’s minor titles as a courtesy title and call himself the Marquess of X or Earl of Y, but he is not a peer and is not allowed to sit in the House of Lords. Younger sons of dukes and marquesses may put Lord in front of their names: Lord John X. Their wives are then called Lady John X. Daughters of dukes, marquesses, and earls will similarly put Lady before their names: Lady Mary Y. Wives of other kinds of peers, and of knights and baronets, are referred to as Lady X or Lady Y; that is, their first names are not used. Sir John Blogg’s wife is simply Lady Blogg, not Lady Mary Blogg. Life peers are people of distinction who are elevated to the peerage but whose titles die with them.