Oldenburg is an independent city in the district of Oldenburg in the state of Lower Saxony, Germany. The city is officially named Oldenburg (Oldb) (Oldenburg in Oldenburg) to distinguish from Oldenburg in Holstein. Archaeological finds point to a settlement dating back to the 8th century. The first documentary evidence, in 1108, referenced Aldenburg in connection with Elimar I (also known as Egilmar I) who is now commonly seen as the first count of Oldenburg. In 1667, the town was struck by a disastrous plague epidemic and, shortly after, a fire destroyed Oldenburg. After the German government announced the abdication of Emperor Wilhelm II (9 November 1918) following the exhaustion and defeat of the German Empire in World War I, monarchic rule ended in Oldenburg as well with the abdication of Grand Duke Frederick Augustus II of Oldenburg (Friedrich August II von Oldenburg) on 11 November 1918. Sea salt production in the Oldenburg region has been used since the 15th century to supply the huge salt demand in the Baltic region. Peat extraction in the area continued for many centuries until it was replaced by coal mines. Kultursommer (summer of culture), series of free musical and other cultural events in the city centre during summer holiday season in July. Stadtfest, a three-day festival of the city centre in August/September, comprises gastronomical offerings and rock and pop music performances on various stages. Oldenburg Central Station is at the intersection of the railway lines Norddeich Mole—Leer—Oldenburg—Bremen and Wilhelmshaven—Oldenburg—Osnabrück, with Intercity services to Berlin, Leipzig and Dresden and InterCityExpress services to Frankfurt and Munich. Oldenburg is connected to shipping through the Küstenkanal, a ship canal connecting the rivers Ems and Weser. With 1.6 million tons of goods annually, it is the most important non-coastal harbour in Lower Saxony. Bicycles play a very important part in personal transport.