The first settlements in the territory of the Republic of Tatarstan date back to the Palaeolithic period (about 100,000 years ago). The first state – the Volga-Kama Bulgaria – was set up at the end of the 9th – beginning of the 10th centuries it was the first feudal state in north-eastern Europe. In 922 Islam was accepted as a state religion. The Bulgar mosques and madrasah (Muslim cleric schools) spread knowledge and culture in the neighbouring regions. In the 13th century, the territory of the Volga-Kama Bulgaria was annexed to the Empire of Genghis-Khan and then became a part of the powerful Zolotaya Orda (Golden Horde) State. The collapse of the Golden Horde in the thirties-forties of the 14th century resulted in the formation of a number of new states including the Kazan Khanate (1445). Kazan became the capital of the newly formed state. The Kazan Khanate ceased its existence in October 1552, after a two-month siege when troops of Ivan IV (the Terrible), numbering 150,000 people, conquered Kazan. A path-breaking step on the way to the restoration of the statehood of the Tatar people was the declaration of the Tatar Autonomous Soviet Socialist Republic in 1920. The end of this century brought new opportunities for the development of the statehood of Tatarstan. On August 30, 1990, the Supreme Soviet of Tatarstan announced the Declaration of State Sovereignty of the republic, later supported by 61% of referendum participants held in March 1992. In 1994 the republic officially got the name of Tatarstan. In March 2008 the republic was declared a part of the Russian Federation.