The postwar period of Katowice was characterised by the time of heavy industry development in the Upper Silesian region, which helped the city in regaining its status as the most industrialised Polish city and a major administrative centre. As the city developed so briskly, the 1950s marked a significant increase in its population and an influx of migrants from the Eastern Borderlands, the so-called "Kresy". The city area began to quickly expand by incorporating the neighbouring communes and counties. However, the thriving industrial city also had a dark period in its short but meaningful history. Most notably, between 7 March 1953 and 10 December 1956, Katowice was called "Stalinogród" in honour of Joseph Stalin, leader of the Soviet Union. The change was brought upon by an issued decree of the State Council. The date of the alteration of the city name was neither a coincidence or accidental as it happened on the day of Stalin's death. In this way, the Polish Communist Party and the socialist authority wanted to pay tribute to the dictator. The new name never got accepted by the citizens and in 1956 the former Polish name was restored.