The County of Oldenburg/Oldenbørg is Denmark's southernmost county. Internally it borders the county of Cuxhaven which lies to the east. Internationally it borders the Holy Roman Empire states of Fryslân, Munster-Westphalia, Wildeshausen, Minden, Hoya and Bremen. The capital is Oldenborg/Oldenbørg and the population is around 516,000.
Its core was once an independent state within the Holy Roman Empire, frequently at war with its Frisian neighbours, and with Bremen and Munster too. Oldenburg would join the Schmalkaldic League in 1533 and Duke Johann VII's conduct during the Second Schmalkaldic War was rewarded with confiscated church lands, the title of Prince and an electorate in the new Protestant Empire after 1558. In 1619, after Schmalkaldic troops captured Prague following its revolt against Austrian tyranny, Prince William-George would be elected King of Bohemia. Surrounded, his reign would last only until 1621 and he would be imprisioned by Austria, where he would die, in 1629. The Principality of Oldenburg passed to his only heir, his infant daughter Catherine, who was also elected 'Queen of Bohemia, in absentia' shortly afterwards by the Czech nobles in exile. As she would be married to the future Christopher IV in 1637 Oldenburg (and a claim on Bohemia) would henceforth pass to Catherine and Christopher's heirs.
In 1649 the territories of the now-defunct Archbishopric of Bremen was added to Oldenburg, as was Jever which had been in Danish hands since 1598. Hamburg followed in 1662. However Denmark moved the government of its German lands to Hamburg and following the Treaty of Copenhagen which confirmed Danish ownership, the whole entity was united as the 'Kingdom of Lower Saxony'.
By the Treaty of Rae the Crown of Lower Saxony was abolished, its territories united with the Danish crown and its lands divided into the counties of Oldenburg and Cuxhaven.
A small Diet with limited powers governs the county and is elected every five years.
Frisian is taught as a second language in the North-West, German prevails in the rest of the county. Danish of course is taught first and foremost as part of Denmark's controversial Langugage Laws. During the 1980s a terrorist organisation staged bombings and assassinations, aimed at uniting the Frisian areas with Fryslan. There are still occasional calls for the Frisian portion to be separated into its own county.