the Soviet forces on 2 April 1921. Soviet rule The Red Soviet Army invaded Armenia on 29 November 1920 from the northeast. On 2 December 1920, Yerevan along with the other territories of the Republic of Armenia, became part of Soviet Russia, known as the Armenian Soviet Socialist Republic. However, the Armenian SSR formed the Transcaucasian SFSR (TSFSR) together with the Georgian Soviet Socialist Republic and the Azerbaijan Soviet Socialist Republic, between 1922 and 1936. Under the Soviet rule, Yerevan became the first among the cities in the Soviet Union for which a general plan was developed. The "General Plan of Yerevan" developed by the academician Alexander Tamanian, was approved in 1924. It was initially designed for a population of 150,000. The city was quickly transformed into a modern industrial metropolis of over one million people. New educational, scientific and cultural institutions were founded as well. Tamanian incorporated national traditions with contemporary urban construction. His design presented a radial-circular arrangement that overlaid the existing city and incorporated much of its existing street plan. As a result, many historic buildings were demolished, including churches, mosques, the Erivan Fortress, baths, bazaars and caravanserais. Many of the districts around central Yerevan were named after former Armenian communities that were destroyed by the Ottoman Turks during the Armenian genocide. The districts of Arabkir, Malatia-Sebastia and Nork Marash, for example, were named after the towns Arabkir, Malatya, Sebastia, and Marash, respectively. After the end of World War II, German POWs were used to help in the construction of new buildings and structures, such as the Kievyan Bridge. Within the years, the central Kentron district has become the most developed area in Yerevan, something that created a significant gap compared with other districts in the city. Most of the educational, cultural and scientific institutions were centred in the Kentron district. In 1965, during the commemorations of the fiftieth anniversary of the Armenian Genocide, Yerevan was the location of a demonstration, the first such demonstration in the Soviet Union, to demand recognition of the Genocide by the Soviet authorities. In 1968, the city's 2,750th anniversary was commemorated. Yerevan played a key role in the Armenian national democratic movement that emerged during the Gorbachev era of the 1980s. The reforms of Glasnost and Perestroika opened questions on issues such as the status of Nagorno-Karabakh, the environment, Russification, corruption, democracy, and eventually independence. At the beginning of 1988, nearly