Duchy of Kopanica (Polish: Księstwo Kopanickie, German: Herzogtum Köpenick) was a Slavonic principality in Central Europe in present day central and eastern Brandenburg. Its capital was Kopanica (German: Köpenick, today part of Berlin).
The Duchy was probably established in the early 12th century. It was a fief of Poland in the mid-12th century. It's only ruler known by name was Jaxa of Köpenick.
The Duchy was centered on the Slavonic stronghold Kopanica. In the late 12th century, in the west and the south it bordered the Holy Roman Empire and in the east the Kingdom of Poland.
From 1153/1154 to 1157 the Slavic settlement Brennabor was part of the Duchy, until it was conquered by Albert the Bear and under the German name of Brandenburg it became capital of the newly established March of Brandenburg.
A duchy (spelled with capital D when it is part of a country's name or a title of a head of state) is a country, territory, fief, or domain ruled by a duke or duchess. The term is used almost exclusively in Europe, where in present-day there is no sovereign Duchy (i.e. with the status of a nation state) left.
The term "Duke" (resp. "Duchy") should not be confounded with the title "Grand Duke" (resp. "Grand Duchy", such as the present-day Grand Duchy of Luxembourg), as there exists a significant difference of rank between the two.
In common European cultural heritage, a Grand Duke is the third highest monarchic rank, after Emperor and King. Its synonym in many eastern European languages (Russian, Lithuanian etc.) is Grand Prince, whereas most western European languages (English, French, Spanish, Italian etc.) use the expression Grand Duke. Unlike a duke, the sovereign Grand Duke is considered to be part of "Royalty" (i.e. royal nobility, in German: Königsadel). The correct form of address is His Royal Highness (HRH).
Among the Lombards, the duke or dux was the man who act as political and military commander of a set of "military families" (the Fara), irrespective of any territorial appropriation.
The proper Lombard language term for the figure of the duke is not known; the oldest Lombard historiographical sources (the anonymous Origo gentis Langobardorum and Historia Langobardorum of Paul Deacon) were written in Latin. The Latin word dux was adopted to designate a political and military figure that had no exact equivalent in the classical world, thus redefining the concept of "duke" in a form that would continue to develop in later centuries.
The figure of the Duke emerged between the 4th and 5th centuries, after the German people settled between the Elbe and the current northern Bohemia. At that time the Lombards were nomads, forming homogeneous groups and compact families originating from the same noble clan, and able to organize themselves into quotas with military functions: the Fare. The Dukes were the leaders of the Fare. In that office they were honored as warriors for the dynastic ties and their valor shown in war, and later rewarded by the king. The figure of the Lombard Duke encompassed a mixture of military, noble, sacral (invested by the king, attended his "charisma"), political, judicial and administrative elements. In the assembly of the people in arms ( "Gairethinx"), the dukes had a prominent role, and were decisive in the election of the king.
The Duchy or Ducatus (Hungarian: dukátus or hercegség) is the denomination for territories occasionally governed separately by members (dukes) of the Árpád dynasty within the Kingdom of Hungary in the 11th-12th centuries. The symbol of the ducal power was a sword, while the royal power was represented by the crown.
Modern historians do not share a consensual view on the origins of the Duchy or territorial units administered by members of the royal family within the medieval Kingdom of Hungary.György Györffy writes that the Ducatus or "Duchy" developed from the command over the Kabars and other ethnic groups which joined the federation of the Hungarian tribes. According to his opinion, this command was initially, even before the Hungarian conquest of the Carpathian Basin around 895, bestowed upon the heir to the supreme head of the Hungarian tribal federation, in accordance with the customs of the Turkic peoples of the Eurasian steppes. Therefore, Györffy continues, the crown prince's command over these ethnic groups transformed, in the course of the 10th century, into his authority over the territories where they settled. Tringli says that it is possible that Koppány's domains in Transdanubia and Saint Emeric's territories (he bore the title of Duke of Russians) were duchies too in accordance with steppe tradition. On the other hand, Gyula Kristó, who refused Györffy's theory, writes that the Duchy only came into being when King Andrew I of Hungary granted one third of his kingdom to his younger brother, Béla around 1048. He cites the Illuminated Chronicle which clearly states that this was the "first division of the kingdom".