duke: holder of highest rank of dignity in peerage (2), called a dukedom. The female equivalent is duchess. The word derives from the Latin dux, a military leader or general under the Roman Empire as early as the 2nd century AD who was usually appointed to command troops in a specific campaign. In later centuries he tended to be put in charge of a border region as the equivalent of the modern General Officer Commanding. Similar officials existed in the Merovingian and Carolingian Empires of a few hundred years later. As royal power declined in the 10th century dukes acquired more independence. Meanwhile a class of non-official military leaders developed and where they managed to establish themselves as independent sovereign rulers they kept the title duke as opposed to king. The Dukes of Normandy constitute the example most relevant to English history.

It is often said that the title duke was unknown in England till it was conferred on the Black Prince in 1337, but Kings from WILLIAM I (THE CONQUEROR) down to EDWARD III from the moment of his accession styled themselves Duke of Normandy, Duke of the Normans or Duke of Aquitaine as well as being known by their regal titles. Sixty years later RICHARD II made up for lost time, as it were, when he created five dukedoms in a single day. This is still the record for peerage creations combining both profusion and eminence of rank. He had already created a life dukedom, that of Ireland, conferring it on his close friend the 9th Earl of Oxford (see SAINT ALBANS). In Scotland the first dukedom, that of Rothesay (see ROYAL FAMILY section PRINCE OF WALES), was created in 1398.

Those on whom dukedoms were conferred were always close blood relatives of the sovereign till the 16th century, and even then the first wholly non-royal creation, Charles Brandon, made Duke of Suffolk in 1514, was HENRY VIII's brother-in-law. By the latter half of ELIZABETH I's reign a series of Acts of attainder had totally eliminated dukedoms from the English peerage. The order revived in the 17th and 18th centuries and during the latter period there were at one time 50 extant, though held by only 40 persons, more than has ever been the case since. Dukedoms by now had tended to become the crowning glory for very rich noblemen who controlled several seats in the House of Commons. Two notable exceptions were those of Marlborough and Wellington, awarded for military success and therefore closer in spirit to the original purpose of a dux or duke.

Among those who are reliably reported to have refused dukedoms are the 3rd Marquess of Lansdowne (qv), Disraeli, following his diplomatic triumph at the Congress of Berlin, and Sir Winston Churchill (see MARLBOROUGH) on his retirement from the premiership in 1955. On the last occasion Buckingham Palace is said to have declared to Sir Jock Colville (see COLVILLE OF CULROSS), Churchill's Principal Private Secretary, that no dukedoms would ever again be conferred on non-royals but that the offer would be made to Churchill on the understanding that he was certain to turn it down.

A duke is addressed or referred to formally as 'Yours/His Grace' and addressed less formally as 'Duke'. For his eldest son's style of address see courtesy title. His younger sons and all daughters are referred to as '(The) Lord John Manners/(The) Lady Diana Manners' (see earl for discussion of the definite article before 'Lord'/'Lady'). A duchess is addressed or referred to formally as 'Your/Her Grace' but a duke's divorced wife should not be, though the late Margaret Duchess of Argyll (the correct way of referring to a divorced wife of a duke) campaigned doggedly to retain the prefix.

A related expression, the Dukeries, describes an area of Nottinghamshire rich in estates or mansions that have historically belonged to dukes: Clumber House (Dukes of Newcastle; see LINCOLN, E), Thoresby House (Dukes of Kingston; see KINGSTON), Welbeck Abbey (Dukes of Portland; see PORTLAND, E), Worksop Manor (Dukes of Norfolk; qv).