Saxony sided with Prussia against France early in the French Revolutionary Wars but changed sides in 1806. For this act its elector was raised to royal rank, becoming King Frederick Augustus I. His failure to change sides again before Napoleon's fall cost him (1815) nearly half his kingdom at the Congress of Vienna. The Kingdom of Saxony lost Lower Lusatia, part of Upper Lusatia, and all its northern territory including Wittenberg and Merseburg to Prussia. Its principal remaining cities were Dresden, Leipzig, Chemnitz, and Plauen. The larger part of the territories ceded in 1815 was incorporated with several other Prussian districts into the Prussian province of Saxony, with Magdeburg as its capital. This was united after 1945 with Anhalt to form the state of Saxony-Anhalt and became part of the German Democratic Republic (East Germany) in 1949. From 1952 to 1990 Saxony-Anhalt was divided into the East German districts of Halle and Magdeburg. In 1990, prior to German reunification, the districts were reintegrated as a state.