By Otto's marriage to Eilika, daughter of Magnus, Duke of Saxony, the Ascanians became heirs to half of the property of the House of Billung, former dukes of Saxony.

(, ), on the river Leine, is the capital of the federal state of Lower Saxony ( Niedersachsen ), Germany and was once by personal union the family seat of the Hanoverian Kings of Great Britain, under their title as the dukes of Brunswick-Lüneburg ( later described as the Elector of Hanover ).

From 1657 to 1738 Merseburg was the residence of the dukes of Saxe-Merseburg, after which it fell to the Electorate of Saxony.

For example, the Obotrites evolved from the unification of the Holstein and Western Mecklenburg tribes led by mighty dukes known for their raids into German Saxony.

The Billung dukes of Saxony were:

From 1485, it was the seat of the dukes of Saxony, and from 1547 the electors as well.

The four major dukes of Germany ( Henry II of Bavaria, Conrad I of Swabia, Henry III of Carinthia, and Bernard I of Saxony ) also paid tribute to the child king.

The importance of Wittenberg historically was due to its seat of the Elector of Saxony, a dignity held by the dukes of Saxe-Wittenberg and also to its close connection with Martin Luther and the dawn of the Protestant Reformation ; several of its buildings are associated with the events of this time.

The elder branch of the House of Este, the House of Welf, historically rendered " Guelf " or " Guelph " in English, produced dukes of Bavaria ( 1070 – 1139, 1156 – 1180 ), dukes of Saxony ( 1138 – 1139, 1142 – 1180 ), a German King ( 1198 – 1218 ), and the dukes of Brunswick and Lüneburg ( 1208 – 1918 ), later styled the " Electors of Hanover " when two branches of the family recombined in 1705.

Born in Ravensburg, he was the son of Henry the Proud, Duke of Bavaria and Saxony, who was the son of Duke Henry the Black and an heir of the Billungs, former dukes of Saxony.

The Saxon dukes, however, continued to rule central Holstein, and when Lothair of Supplinburg became duke of Saxony ( 1106 ), on the extinction of the Billung line, he enfeoofed Lord Adolphus of Schauenburg with the County of Holstein, as a Saxon subfief, becoming Adolphus I, Count of Holstein with the Saxon, later Lower Saxon dukes as liege lords.

In 911 the East Frankish Carolingian dynasty became extinct with the death of King Louis the Child, whereafter the dukes of Saxony, Swabia and Bavaria met at Forchheim to elect the Conradine duke Conrad I of Franconia king.

Matthias consolidated his position by alliances with the dukes of Saxony and Bavaria, with the Swiss Confederation and the archbishop of Salzburg, establishing henceforth the greatest potentate in central Europe.

The city of Bergedorf received town privileges in 1275, then a part of the younger Duchy of Saxony ( 1180 – 1296 ), which was partitioned by its four co-ruling dukes in 1296 into the branch duchies of Saxe-Lauenburg and Saxe-Wittenberg.

According to the Res gestae saxonicae by chronicler Widukind of Corvey, Conrad on his deathbed persuaded his younger brother Eberhard to offer the crown to Henry the Fowler, the duke of Saxony and one of his principal opponents, since he considered Henry to be the only prince capable of holding the German kingdom together in the face of internal rivalries among the dukes and the continuous Hungarian raids.

Elimar's ancestors appear as vassals, though sometimes rebellious ones, of the dukes of Saxony ; but they attained the dignity of princes of the empire when the emperor Frederick I dismembered the Saxon duchy in 1180.

The Prussian king, Frederick II, joined by the dukes of Bavaria and Saxony, invaded the Bohemian Kingdom in 1741.

The House of Wettin is a dynasty of German counts, dukes, prince-electors ( Kurfürsten ) and kings that once ruled the area of today's German states of Saxony, the Saxon part of Saxony-Anhalt, and Thuringia for more than 800 years.

By the month's end, Hannover, the Hessian dukes, Brandenburg and Saxony were officially aligned against the empire, and France had agreed to provide substantially greater funding for Gustav's armies.

* Dachau Palace: a medieval castle which became the favourite residence of the Bavarian dukes in the 16th century.

Restored twice with the support of both Emperor and Pope, the Medici in 1537 became hereditary dukes of Florence, and in 1569 Grand Dukes of Tuscany, ruling for two centuries.

At this time, many local dukes saw it as a chance to oppose the hegemony of Emperor Charles V. The empire then became fatally divided along religious lines, with the north, the east, and many of the major cities — Strasbourg, Frankfurt and Nuremberg — becoming Protestant while the southern and western regions largely remained Catholic.

The Electors of Regensburg ( who had succeeded to the Mainz vote ), Würzburg ( who had succeeded to the Salzburg vote ), and Baden ( a new electorate ) became grand dukes.

After Boleslaw's death, the Duchy of Pomerania regained independence, before the dukes became vassals of Denmark and the Holy Roman Empire in the late 12th century.

In 1345, the bishops became Imperial immediate dukes in their secular reign.

It became the residence of the dukes of Lower Silesia in 1163 and was the seat of a principality ruled from 1248-1675.

The Zähringer dynasty ended with the death of Berchtold V in 1218, and their cities subsequently became reichsfrei ( essentially a city-state within the Holy Roman Empire ), while the dukes of Kyburg competed with the house of Habsburg over control of the rural regions of the former Zähringer territory.

The Conradines became dukes of Franconia, while the Babenbergs lost their influence in Franconia.

Both Schleswig and Holstein were therefore administered from Copenhagen, even after the Empire's dissolution, when the Danish kings as dukes of Holstein became monarchs of the German Confederation in 1815.

In 1721, when the Great Northern War ended, the dukes of Gottorf lost their power and their land became Danish crown land.

In 1260, it became the residence of the dukes of Saxe-Wittenberg, and in 1293 the settlement was granted a town charter.

In the 10th century Rouen became the capital of the Duchy of Normandy and residence of the dukes, until William the Conqueror established his castle at Caen.

With the death of Ottokar the first line of rulers of Styria became extinct ; the region fell successively to the Babenberg family, rulers of Austria, as stipulated in the Georgenberg Pact ; after their extinction to the control of Hungary ( 1254 – 60 ); to King Ottokar of Bohemia ; in 1276 to the Habsburgs, who provided it with Habsburgs for Styrian dukes during the years 1379-1439 and 1564-1619.

In 1514, Charles of Egmond, duke of Guelders, took it from the dukes of Burgundy ; in 1543, it fell to the emperor Charles V. As capital of the so-called " Kwartier van Veluwe " it joined the Union of Utrecht in 1579 and became part of the Republic of the Seven United Provinces of the Netherlands in 1585.

All five of Edward III's surviving sons eventually became dukes.

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.

During the rule of the Árpád dinasty dukes held territorial powers, some of them even minted coins, but later this title became more often nominal.

The dukes of Burgundy systematically became the lord of different provinces.

* Visconti, the leading noble family that became ruling dukes of Milan, apparently taking its surname from a returning crusader Ottone who was created Visconte of Milan

When the Danes had to surrender the Pomeranian lands south of the Ryck after losing the Battle of Bornhöved in 1227, the town became of particular interest to the Pomeranian dukes.

In 1793 the bathing resort of Heiligendamm ( today a borough of Bad Doberan ) was established, and the region became a summer residence for the dukes of Mecklenburg-Schwerin.

The Varangian dynasty of Ruriks became dukes in the neighboring Duchy of Kiev.