Eisleben was first written about in 997 as a market called Islebia, and in 1180 as a town. The counts of Mansfeld governed the area until the 18th century. In 1780, Eisleben came directly under the Electorate of Saxony. After the Napoleonic Wars, Eisleben became part of the Kingdom of Prussia. The Prussian Province of Saxony became part of the Free State of Prussia in the German Reich after World War I. After World War II, Eisleben became part of the new state of Saxony-Anhalt in the German Democratic Republic (GDR) until Germany's reuinification in 1990.