could be opened in reconstructed facilities or interim exhibitions. Important orchestras such as the Staatskapelle performed in alternative venues (for example in the Kulturpalast from 1969). Some cultural institutions were moved out of the city center (for example the state library in Albertstadt). The Outer Neustadt, which was almost undamaged during the war was threatened with demolition in the 1980s following years of neglect, but was preserved following public protests. To house the homeless large prefabricated housing estates were built on previously undeveloped land In Prohlis and Gorbitz. Damaged housing in the Johannstadt and other areas in the city center were demolished and replaced with large apartment blocks. The villa districts in Blasewitz, Striesen, Kleinzschachwitz, Loschwitz and on the Weißen Hirsch were largely preserved. Dresden became a major industrial centre in the German Democratic Republic (former East Germany) with a great deal of research infrastructure. It was the centre of Bezirk Dresden (Dresden District) between 1952 and 1990. Many of the city's important historic buildings were reconstructed, including the Semper Opera House and the Zwinger Palace, although the city leaders chose to rebuild large areas of the city in a "socialist modern" style, partly for economic reasons, but also to break away from the city's past as the royal capital of Saxony and a stronghold of the German bourgeoisie. Until the end of the Cold War, the 1st Armored Guard Army of the Soviet Army and the 7th Panzer Division of the National People's Army were stationed in and around Dresden. Following reunification in 1989, the Soviet / Russian troops were withdrawn from Germany in the early 1990s and the NVA dissolved in accordance with the provisions of the Two-Plus-Four Treaty of 1990. From 1985 to 1990, the future President of Russia, Vladimir Putin, was stationed in Dresden by the KGB, where he worked for Lazar Matveev, the senior KGB liaison officer there. On 3 October 1989 (the so-called "battle of Dresden"), a convoy of trains carrying East German refugees from Prague passed through Dresden on its way to the Federal Republic of Germany. Local activists and residents joined in the growing civil disobedience movement spreading across the German Democratic Republic, by staging demonstrations and demanding the removal of the communist government. Post-reunification Dresden has experienced dramatic changes since the reunification of Germany in the early 1990s. The city still bears many wounds from the bombing raids of 1945, but