|Prince / Infante|
|Sovereign Prince / Fürst|
|Marquess / Marquis /
Margrave / Landgrave
|Count / Earl|
|Viscount / Vidame|
A duke (male) (British English: // or American English: //) 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 (as Herzog) 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 an institution similar to the peerage (e.g., Grandeeship, Imperial Diet, Hungarian House of Magnates) existed.
During the 19th century many of the smaller German and Italian states were ruled by Dukes or Grand Dukes. But at present, with the exception of the Grand Duchy of Luxembourg, there are no dukes ruling as monarchs. Duke remains the highest hereditary title (aside from titles borne by the reigning or formerly reigning dynasty) in Portugal (though now a republic), Spain, and the United Kingdom. In Sweden, members of the Royal Family are given a personal dukedom at birth. The Pope, as a temporal sovereign, has also, though rarely, granted the title of Duke or Duchess to persons for services to the Holy See. In some realms the relative status of "duke" and "prince", as titles borne by the nobility rather than by members of reigning dynasties, varied—e.g., in Italy and the Netherlands.
A woman who holds in her own right the title to such duchy or dukedom, or is the wife of a duke, is normally styled duchess. Queen Elizabeth II, however, is known by tradition as Duke of Normandy in the Channel Islands and Duke of Lancaster in Lancashire.
- 1 Duchy versus dukedom
- 2 Middle Ages
- 3 The modern age
- 4 Equivalents in other European languages
- 5 Royal dukes
- 6 France
- 7 Italy, Germany and Austria
- 8 Elsewhere in Europe
- 9 Post-colonial non-European states
- 10 Equivalents
- 11 See also
- 12 Notes
- 13 References
Duchy versus dukedom
A duchy is the territory or geopolitical entity ruled by a duke. The term implies a territorial domain, within which the duke has actual subjects or significant land holdings, with respect to which the duke has or had unique legal privileges, e.g., sovereignty or manorial rights or entitlement to certain duties or income from residents (e.g., the corvée), etc. A dukedom is the title or status of a duke, a rank in the present or past nobility, and is not necessarily attached to a duchy. A few examples exist today: The Grand Duchy of Luxembourg is a fully independent state and its head, the Grand Duke, is a sovereign monarch reigning over his Luxembourgish subjects. The Duke of Cornwall holds both the dukedom (title) and duchy (estate holdings), the latter being the source of his personal income; those living on the ducal estates are subjects of the British sovereign and owe neither fealty nor services to the duke per se. In Scotland the male heir apparent to the British crown is always the Duke of Rothesay as well, but this is a dukedom (title) without a duchy. Similarly, the British monarch rules and owns the Duchy of Lancaster as Duke of Lancaster, but it is held separately from the Crown, with the income of the duchy estates providing the Sovereign's Privy Purse. The Channel Islands are two of the three remaining Crown Dependencies, the last vestiges of the lands of the Duchy of Normandy. The Islanders in their loyal toast will say "La Reine, notre Duc" (The Queen, Our Duke). Though the title was apparently renounced under the Treaty of Paris in 1259, the Crown still maintains that the title is retained: "In 1106, William's youngest son Henry I seized the Duchy of Normandy from his brother Robert; since that time, the English Sovereign has always held the title Duke of Normandy," and that "By 1205, England had lost most of its French lands, including Normandy. However, the Channel Islands, part of the lost Duchy, remained a self-governing possession of the English Crown. While the islands today retain autonomy in government, they owe allegiance to The Queen in her role as Duke of Normandy."
During the Middle Ages, after Roman power in Western Europe collapsed, the title was still employed in the Germanic kingdoms, usually to refer to the rulers of old Roman provinces.
In 1332, Robert of Taranto succeeded his father, Philip. Robert's uncle, John, did not wish to do him homage for the Principality of Achaea, so Robert received Achaea from John in exchange for 5,000 ounces of gold and the rights to the diminished Kingdom of Albania. John took the style of Duke of Durazzo (today Durrës).
The Visigoths retained the Roman divisions of their kingdom in the Iberian Peninsula and it seems that dukes ruled over these areas. They were the most powerful landowners and, along with the bishops, elected the king, usually from their own midst. They were the military commanders and in this capacity often acted independently from the king, most notably in the latter period before the Muslim invasions.
The army was structured decimally with the highest unit, the thiufa, probably corresponding to about 1,000 people from each civitas (city district). The cities were commanded by counts, who were in turn answerable to the dukes, who called up the thiufae when necessary.
When the Lombards entered Italy, the Latin chroniclers called their war leaders duces in the old fashion. These leaders eventually became the provincial rulers, each with a recognized seat of government. Though nominally loyal to the king, the concept of kingship was new to the Lombards and the dukes were highly independent, especially in central and southern Italy, where the Duke of Spoleto and the Duke of Benevento were de facto sovereigns. In 575, when Cleph died, a period known as the Rule of the Dukes, in which the dukes governed without a king, commenced. It lasted only a decade before the disunited magnates, in order to defend the kingdom from external attacks, elected a new king and even diminished their own duchies to provide him with a handsome royal demesne.
The Lombard kings were usually drawn from the duke pool when the title was not hereditary. The dukes tried to make their own offices hereditary. Beneath them in the internal structure were the counts and gastalds, a uniquely Lombard title initially referring to judicial functions, similar to a count's, in provincial regions
The Franks employed dukes as the governors of Roman provinces, though they also led military expeditions far from their duchies. The dukes were the highest-ranking officials in the realm, typically Frankish (whereas the counts were often Gallo-Roman), and formed the class from which the kings' generals were chosen in times of war. The dukes met with the king every May to discuss policy for the upcoming year, the so-called Mayfield.
In Burgundy and Provence, the titles of patrician and prefect were commonly employed instead of duke, probably for historical reasons relating to the greater Romanization of those provinces. But the titles were basically equivalent.
In late Merovingian Gaul, the mayors of the palace of the Arnulfing clan began to use the title dux et princeps Francorum: "duke and prince of the Franks". In this title, "duke" implied supreme military control of the entire nation (Francorum, the Franks) and it was thus used until the end of the Carolingian dynasty in France in 987.
Holy Roman Empire
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The highest political division beneath that of kingdom among the Anglo-Saxons was the ealdormanry and, while the title ealdorman was replaced by the Danish eorl (later earl) over time, the first ealdormen were referred to as duces (the plural of the original Latin dux) in the chronicles. So in Anglo-Saxon England, where the Roman political divisions were largely abandoned, the grade of duke was retained as supreme landlord after the king. But after the Norman conquest, their power and regional jurisdiction was limited to that of the Norman counts.
Late medieval times
Edward III of England created the first three English dukedoms (Cornwall, Lancaster, and Clarence) by naming his eldest son Edward, the Black Prince, as Duke of Cornwall in 1337. Upon the death of the Black Prince, the duchy of Cornwall passed to his nine-year-old son, who would eventually succeed his grandfather as Richard II.
The duchy of Lancaster was created by Edward III in 1351 for Henry of Grosmont, but became extinct upon the duke's death in 1361. The following year, Edward III bestowed the title (2nd creation) on his fourth son, John of Gaunt, who was also married to the first duke's daughter. On the same day Edward III also created his second son, Lionel of Antwerp, as Duke of Clarence.
All five of Edward III's surviving sons eventually became dukes. In 1385, ten years after their father's death, his heir Richard II created dukedoms for his last two uncles on the same day. Thomas of Woodstock was named Duke of Gloucester and Edmund of Langley became Duke of York, thereby founding the House of York, which later fought for the throne with John of Gaunt's Lancastrian descendants during the Wars of the Roses.
By 1483, a total of 16 ducal titles had been created: Cornwall, Lancaster, Clarence, Gloucester, York, Ireland, Hereford, Aumale, Exeter, Surrey, Norfolk, Bedford, Somerset, Buckingham, Warwick and Suffolk. Some became extinct, others had multiple creations, and some had merged with the crown upon the holder's accession to the throne. When the Plantagenet dynasty came to an end at the Battle of Bosworth Field on 22 August 1485, only four ducal titles remained extant, of which two were now permanently associated with the crown. John de la Pole was Duke of Suffolk and John Howard was Duke of Norfolk (2nd creation), while the duchy of Cornwall was reserved as a title and source of income for the eldest son of the sovereign, and the duchy of Lancaster was now held by the monarch.
Norfolk perished alongside Richard III at Bosworth field, and the title was forfeit. It was restored to his son Thomas thirty years later by Henry VIII, as one of a number of dukes created or recreated by the Tudor dynasty over the ensuing century. England's premier ducal title, Norfolk, remains in the Howard family to this day.
The modern age
In the 19th century, the sovereign dukes of Parma and Modena in Italy, and of Anhalt, Brunswick-Lüneburg, Nassau, Saxe-Coburg-Gotha, Saxe-Meiningen and Saxe-Altenburg in Germany survived Napoleon's reorganization.
Since the unification of Italy in 1870 and the end of monarchy in Germany in 1918, there have no longer been any reigning dukes in Europe; Luxembourg is ruled by a grand duke, a higher title, just below king.
In the United Kingdom, the inherited position of a duke along with its dignities, privileges, and rights is a dukedom. However, the title of duke has never been associated with independent rule in the British Isles: they hold dukedoms, not duchies (excepting the Duchy of Cornwall and the Duchy of Lancaster). Dukes in the United Kingdom are addressed as "Your Grace" and referred to as "His Grace". Currently, there are twenty-seven dukedoms in the Peerage of England, Peerage of Scotland, Peerage of Great Britain, Peerage of Ireland and Peerage of the United Kingdom, held by twenty-four different people (see List of Dukes in order of precedence).
Equivalents in other European languages
See wikt:en:duke for equivalents in other European languages.
Various royal houses traditionally awarded (mainly) dukedoms to the sons and in some cases, the daughters, of their respective sovereigns; others include at least one dukedom in a wider list of similarly granted titles, nominal dukedoms without any actual authority, often even without an estate. Such titles are still conferred on royal princes or princesses in the current European monarchies of Belgium, Spain, Sweden and the United Kingdom.
Other historical cases occurred for example in Denmark, Finland (as a part of Sweden) and France, Portugal and some former colonial possessions such as Brazil and Haiti.
In the United Kingdom, ducal titles which have been given within the royal family include Duke of Cornwall, Duke of Lancaster, Duke of Clarence, Duke of York, Duke of Gloucester, Duke of Bedford, Duke of Cumberland, Duke of Cambridge, Duke of Rothesay, Duke of Albany, Duke of Ross, Duke of Edinburgh, Duke of Kent, Duke of Sussex, and Duke of Connaught and Strathearn. Following his abdication in 1936 the former King Edward VIII was given the title Duke of Windsor.
- List of dukes in the Peerage of the United Kingdom
- List of dukes in the peerages of the British Isles
In Belgium, the title of Duke of Brabant (historically the most prestigious in the Low Countries, and containing the federal capital Brussels), if still vacant, has been awarded preferentially to the eldest son and heir apparent of the king, other male dynasts receiving various lower historical titles (much older than Belgium, and in principle never fallen to the Belgian crown), such as Count of Flanders (King Leopold III's so-titled brother Charles held the title when he became the realm's temporary head of state as prince-regent) and Prince of Liège (a secularised version of the historical prince-bishopric; e.g. King Albert II until he succeeded his older brother Baudouin I).
Denmark's kings gave appanages in their twin-duchies of Schleswig-Holstein (now three-fourths of them is part of Germany, but then the Holstein half of it was part of the Holy Roman Empire in personal union with Denmark proper) to younger sons and/or their male-line descendants, with a specific though not sovereign title of Duke, e.g., Duke of Gottorp, Duke of Sonderburg, Duke of Augustenborg, Duke of Franzhagen, Duke of Beck, Duke of Glucksburg and Duke of Norburg.
When the Christian Reconquista, sweeping the Moors from the former Caliphate of Córdoba and its taifa-remnants, transformed the territory of former Suevic and Visigothic realms into Catholic feudal principalities, none of these warlords was exactly styled Duke. A few (as Portugal itself) started as Count (even if the title of Dux was sometimes added), but soon all politically relevant princes were to use the royal style of King.
In Portugal, the title of Duke was granted for the first time in 1415 to infante Peter and infante Henry, the second and third sons of king John I, following their participation in the successful Conquest of Ceuta. Pedro became the first Duke of Coimbra and Henry the first Duke of Viseu.
From the reign of king Manuel I, the title of Duke of Beja was given to the second son of the monarch. This was changed during the Liberal regime in the 19th century (with queen Maria II), when the first infante (second son of the monarch) got the title of Duke of Porto and the second infante (third son) was known as Duke of Beja.
There are examples of Duke as a subsidiary title, granted to the most powerful noble Houses:
- Duke of Barcelos, to be used by the heir of the Duke of Braganza;
- Duke of Torres Novas, to be used by the heir of the Duke of Aveiro;
- Duke of Miranda do Corvo, to be used by the heir of the Duke of Lafões.
Usually, the title of Duke was granted to relatives of the Royal Family, such as the infantes or natural sons of the monarch. There are exceptions, such as António José de Ávila, who, although not having any relation to the royal family, was given the title of duke of Ávila and Bolama in the 19th Century.
Spanish infantes and infantas were usually given a dukedom upon marriage, excepting the heir apparent who is the Prince of Asturias. This title is nowadays not hereditary but carries a Grandeza de España. The current royal duchesses are: HRH the Duchess of Badajoz (Infanta Maria del Pilar), HRH the Duchess of Soria (Infanta Margarita) (although she inherited the title of Duchess of Hernani from her cousin and is second holder of that title), HRH the Duchess of Lugo (Infanta Elena) and HRH the Duchess of Palma de Mallorca (Infanta Cristina).
The Northern European duchies of Halland, Jutland, Lolland, Osilia and Reval existed in the Middle Ages. The longest-surviving duchy was Schleswig, i.e., Sonderjylland (a portion of which later became part of Germany). Its southern neighbor, the duchy of Holstein, in personal union with the Danish crown, was nonetheless always a German principality. The two duchies jointly became a member of the German Bundesland as "Schleswig-Holstein" in the 19th century.
In Sweden, medieval duchies of Finland, Södermanland, Skåne, and Halland were some appanages for princes of the reigning dynasty. In modern times almost every province in Sweden was used as the territorial designation for a royal prince's dukedom.
Sweden had a history of making the sons of its kings ruling princes of vast duchies, but this ceased in 1622. Only one non-royal person was ever given a dukedom. Title-wise, however, all Swedish princes since 1772, and princesses since 1980, are given a dukedom for life. Currently, there are two dukes and four duchesses. The territorial designations of these dukedoms refer to six of the Provinces of Sweden.
Key parts of Finland were sometimes under a Duke of Finland during the Swedish reign. Some of the provinces are still considered duchies for the purposes of heraldry.
France and other former monarchies
See appanage (mainly for the French kingdom) and the list in the geographical section below, which also treats special ducal titles in orders or national significance.
The highest precedence in the realm, attached to a feudal territory, was given to the twelve original pairies (en: peers), which also had a traditional function in the royal coronation, comparable to the German imperial archoffices. Half of them were ducal: three ecclesiastical (the six prelates all ranked above the six secular peers of the realm) and three temporal, each time above three counts of the same social estate: The Prince-Bishops with ducal territories among them were:
- The Archbishop of Reims, styled archevêque-duc pair de France (in Champagne; who crowns and anoints the king, traditionally in his cathedral)
- Two suffragan bishops, styled evêque-duc pair de France :
The secular dukes in the peerage of the realm were, again in order of precedence:
- The Duke of Burgundy or duc de Bourgogne (known as Grand duc; not a separate title at that time; just a description of the wealth and real clout of the 15th century Dukes, cousins of the Kings of France) (bears the crown, fastens the belt)
- The Duke of Normandy or duc de Normandie (holds the first square banner)
- The Duke of Aquitaine or duc d'Aquitaine or de Guyenne (holds the second square banner)
It should be noted that the theory of the participation of the peers in the coronation was laid down in the late 13th century, when some of the peerage (the Duchy of Normandy and the County of Toulouse) had already been merged in the crown.
At the end of this same century, the king elevated some counties into duchies, a practice that increased up until the Revolution. Many of this duchies were also peerages (the so-called 'new peerages').
Italy, Germany and Austria
In Italy, Germany and Austria the title of "duke" (duca in Italian, and Herzog in German) was quite common. As the Holy Roman Empire of the German Nation (HRE) was until its dissolution a feudal structure, most of its Dukes were actually reigning in their lands. As the titles from the HRE were taken over after its dissolution, or in Italy after their territories became independent of the Empire, both countries also had a share of fully sovereign dukes. Also, in Germany in many ducal families every agnate would bear the ducal title of the family as a courtesy title.
In Italy some important sovereign ducal families were the Visconti and the Sforza, who ruled Milan; the Capece Minutolo in Naples; the Savoia in Piedmont; the Medici of Florence; the Farnese of Parma and Piacenza; the Cybo-Malaspina of Massa; the Gonzaga of Mantua; the Este of Modena and Ferrara. The maritime republics of Venice and Genoa were ruled by elected Doges, a word which comes from the same Latin root as "Duke".
In Germany, important ducal families were the Wittelsbachs in Bavaria, the Welfs in Hannover, the ducal family of Cleves, the Wettins in Saxony (with its Ernestine branch divided into several duchies), the Württembergs, the Mecklenburgs and the Habsburgs in Austria as "Archdukes". In the German Confederation the Nassaus, the Ascanians of Anhalt, the Welf branch of Brunswick and the Ernestine lines of the Saxon duchies were the sovereign ducal families.
Elsewhere in Europe
In the Kingdom of Hungary no ducal principalities existed but duchies were often formed for members of the dynasty as appanages. During the rule of the Árpád dynasty dukes held territorial powers, some of them even minted coins, but later this title became more often nominal. These duchies usually were
- the Duchy of Nitra
- the Duchy of Bihar
- the Duchy of Transylvania (consisting of the voivodship of Transylvania and some other counties)
In the Jagellonian era (1490–1526) only two dukes did not belong to the royal dynasty: John Corvin (the illegitimate son of Matthias Corvinus) and Lőrinc Újlaki (whose father was the king of Bosnia), and both bore the title as royal dukes.
- the Duchy of Athens, to which the duchy of Neopatras was later linked
- the Aegean insular Duchy of Naxos, officially the "Duchy of the Archipelago"
The Byzantines retained the title dux, transcribed as doux in Greek. As in the later Roman Empire, it remained a military office. In the 10th century, it was given to the military commanders over several themata (also known as katepano), and in the late 11th century it became used for the governor of a thema.
In Italy and other western countries, the later Byzantine appanages of the Palaiologan period were sometimes translated as duchies: the Morea, Mesembria, Selymbria and Thessaloniki. However, as these had Greek holders, they were titled Archon ("magistrate") or Despotes.
Slavic and nearby countries
Generally, confusion reigns whether to translate the usual ruler titles, knyaz/ knez/ ksiaze etc. as Prince (analogous to the German Fürst) or as Duke;
- In splintered Poland petty principalities generally ruled by branches of the earlier Polish Piast dynasty are regarded as duchies in translated titulary. Examples of such: Kujavia, Masovia, Sandomir, Greater Poland and Kalisz as well as various minor duchies, often short-lived and/or in personal union or merger, named after their capitals, mainly in the regions known as Little Poland and Greater Poland, including (there are often also important Latin and/or German forms) Kraków, Łęczyca and Sieradz.
- In Pomerelia and Pomerania (inhabited by the Kashubians, different Slavic people from the Poles proper), branches of native ruling dynasties were usually recognized as dukes, quite similarly to the pattern in Poland.
- In Russia, before the imperial unification from Muscovy; sometimes even as vassal, tributary to a Tartar Khan; later, in Peter the Great's autocratic empire, the russification gertsog was used as the Russian rendering of the German ducal title Herzog, especially as (the last) part of the full official style of the Russian Emperor: Gertsog Shlesvig-Golstinskiy, Stormarnskiy, Ditmarsenskiy i Oldenburgskiy i prochaya, i prochaya, i prochaya "Duke of Schleswig-Holstein [see above], Stormarn, Dithmarschen and Oldenburg, and of other lands", in chief of German and Danish territories to which the Tsar was dynastically linked.
- In Bohemia was Duchy of Krumlov, and short-lived Duchy of Reichstadt and Duchy of Friedland.
- In Silesia were many petty duchies as Duchy of Brzeg, Duchy of Legnica, Duchy of Zator and Duchy of Racibórz. They were vassals of King of Bohemia.
- In Lithuania, the approximate equivalent of a duke or prince was called kunigaikštis in the Lithuanian language. Latin translation was dux meaning "duke" in the Middle Ages, whereas Latin for "prince" is princeps. The overall leader of the Lithuanian dukes (Lith. plural: kunigaigščiai) was the grand duke (Lith.: didysis kunigaikštis, Latin: magnus dux), who acted as the monarch of the Grand Duchy of Lithuania until 1795 when Russians took over the land.
After Belgium and the Netherlands separated in 1830, the title of duke no longer existed in the Netherlands. There is, however, one exception; the title Hertog van Limburg (Duke of Limburg) still exists. This title, however, is an exclusive title for the head of state (the monarch, i.e., the king or queen of the Netherlands).
Post-colonial non-European states
Empire of Brazil
In the Empire of Brazil duke was the highest rank for people born outside the imperial house and only three dukedoms were created. Two of these titles were for relatives of Emperor Pedro I: an illegitimate daughter and a brother-in-law who received the title when married to Pedro I's daughter Maria II. The third, given to Luís Alves de Lima e Silva, was the only dukedom created during the reign of Pedro II. None of these titles were hereditary, just like every other title in the Brazilian nobility system.
The royal Christophe dynasty created eight hereditary dukedoms, in rank directly below the nominal princes. They were short-lived and only recognised in the country.
Like other major Western noble titles, Duke is sometimes used to render (translate) certain titles in non-western languages. "Duke" is used even though those titles are generally etymologically and often historically unrelated and thus hard to compare. However, they are considered roughly equivalent, especially in hierarchic aristocracies such as feudal Japan, useful as an indication of relative rank.
Indian feudal system cannot be fully translated to its European counterparts. The closest equivalent to a Duchy is a large Jagir. Thus, a Jagirdar, Deshmukh, Patil and Zamindar are closely equivalent to a Duke.
During the era of feudalism in Ancient China (Spring and Autumn and the Warring States), the equivalent titles to Grand Marquis or Grand Duke were often granted to the nobility and governors of the individual kingdoms and principalities. Noble titles also existed in subsequent periods.
The Duke of Yansheng noble title was granted to the descendants of Confucius. In 1935, the Nationalist Government changed the title to Sacrificial Official to Confucius (大成至聖先師奉祀官), which still exists as an office of the Republic of China, de facto hereditary.
Nonhereditary dukedoms and other lesser titles were also awarded, sometimes posthumously (see posthumous names), during the imperial period of Chinese history to recognize distinguished civil and military officials without the burdens of supporting a feudal peerage. For example, Emperor Lizong of Song granted the posthumous title Duke of Hui (徽国公) to the Neo-Confucian thinker Zhu Xi.
The Javanese kingdom of Majapahit, which dominated eastern Java in the 14th and 15th centuries, was divided into nagara (provinces). The administration of these nagara was entrusted to members of the royal family, who bore the title of Bhre—i.e., Bhra i, "lord of" (the word bhra being akin to the Thai Phra), followed by the name of the land they were entrusted with: for example a sister of king Hayam Wuruk (r. 1350–1389) was "Bhre Lasem", "lady of Lasem". This system was similar to the Apanage system in Western Europe.
Sultan Agung, king of Mataram in Central Java (r. 1613–1645), would entrust the administration of territories he gradually conquered all over the island of Java, to officials bearing the title of Adipati, this title is hereditary. Such territories were called Kadipaten.
The VOC (Dutch East Indies Company), while gradually taking control of Javanese territory, would maintain the existing Mataram administrative structure. Adipati were called "regenten" in Dutch, and the territories they administered, "regentschappen".
In the 19th century, the Javanese term for regent was bupati. French traveller Gérard Louis Domeny de Rienzi mentions bapati.
- List of dukes in the peerages of the British Isles
- Duchies in Sweden
- Duchy of Amalfi
- Duchy of Brittany
- Duchy of Gaeta
- Duchy of Naples
- "British English: Duke". Collins Dictionary. n.d. Retrieved 23 September 2014.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- "American English: Duke". Collins Dictionary. n.d. Retrieved 23 September 2014.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- Crouch p108
- see Dukes of Lancaster
- Duke Yansheng
- Chan p34
- *Grégoire Louis Domeny de Rienzi, Océanie ou cinquième partie du monde : revue géographique et ethnographique de la Malaisie, de la Micronésie, de la Polynésie et de la Mélanésie, ainsi que ses nouvelles classifications et divisions de ces contrées, Firmin Didot Frères, Paris, 1834
- Chan, Wing-tsit, Chu Hsi New Studies. University of Hawaii Press: 1989. ISBN 978-0-8248-1201-0
- Crouch, David, The Normans (2002) ISBN 1-85285-387-5
- Hodgkin, Thomas. Italy and her Invaders. Clarendon Press: 1895.
- Lewis, Archibald R. "The Dukes in the Regnum Francorum, A.D. 550-751." Speculum, Vol. 51, No 3 (July 1976), pp 381–410.
- Stenton, Sir Frank M. Anglo-Saxon England Third Edition. Oxford University Press: 1971.
- Thompson, E. A. The Goths in Spain. Clarendon Press: Oxford, 1969.