Location of the later Duchy of Oldenburg within the Holy Roman Empire+.
Created on breakup of Saxony+
Raised to duchy
Annexed by France+
Re-established as a grand duchy+
The first known count of Oldenburg is Elimar I+ (d. 1108). Elimar's descendants 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. At this time, the county of Delmenhorst+ formed part of the dominions of the counts of Oldenburg, but afterwards it was on several occasions separated from them to form an appanage+ for younger branches of the family. This was the case between 1262 and 1447, between 1463 and 1547, and between 1577 and 1617.
During the early part of the 13th century the counts carried on a series of wars with independent, or semi-independent, Frisian+ princes to the north and west of the county, which resulted in a gradual expansion of the Oldenburgian territory. The Free Hanseatic City of Bremen+ and the bishop of Münster+ were also frequently at war with the counts of Oldenburg.
In 1440, Christian succeeded his father Dietrich+, called '''', as Count of Oldenburg. In 1448 Christian was elected king of Denmark+ as Christian I+, partly based on his maternal descent from previous Danish kings. Although far away from the Danish borders, Oldenburg was now a Danish exclave+. The control over the town was left to the king's brothers, who established a short reign of tyranny.
Early in the 16th century Oldenburg was again enlarged at the expense of the Frisians. Lutheranism+ was introduced into the county by Anthony I+ (1505–73, r. from 1529), who also suppressed the monasteries; however, he remained loyal to Emperor Charles V+ during the Schmalkaldic War+, and was able thus to increase his territories, obtaining Delmenhorst+ in 1547. One of Anthony's brothers, Christopher+ (about 1506–60), won some reputation as a soldier.
Anthony's grandson, Anthony Günther+ (1583–1667), who succeeded in 1603, considered himself the wisest prince who had yet ruled Oldenburg. Jever+ had been acquired before he became count, but in 1624 he added Kniphausen+ and Varel+ to his lands, with which in 1647 Delmenhorst was finally united. By his neutrality during the Thirty Years' War+ and by donating valuable horses to the warlord, the Count of Tilly+, Anthony Günther secured for his dominions an immunity from the terrible devastations to which nearly all the other states of Germany were exposed. He also obtained from the emperor the right to levy tolls+ on vessels passing along the Weser+, a lucrative grant which soon formed a material addition to his resources. In 1607 he erected a Renaissance+ castle. After the death of Anthony Günther, Oldenburg fell again under Danish authority.
By the beginning of World War II+ in 1939, as a result of these territorial changes, Oldenburg had an area of and 580,000 inhabitants.
In 1946, after World War II, Oldenburg merged into the newly founded state of Lower Saxony+ forming, territorially unchanged, the administrative region ('''') of Oldenburg. Region and State both became a part of West Germany+ in 1949. The administrative region was abolished in 1978 and merged with neighbouring governorates ('''') into the new region of Weser-Ems+, dissolved in 2004.
Lower Rhenish–Westphalian Circle:
States of the Confederation of the Rhine:
Duchy of Oldenburg+ The Duchy of Oldenburg () — named after its capital, the town of Oldenburg — was a state in the north-west of present-day Germany.