Русское царство, or the Russian Kingdom, emerged in the late 15th century when Ivan III unified various principalities and declared Moscow as the center of power. This period marked the transition from the fragmented Kievan Rus to a centralized state, laying the foundation for the future Russian Empire. The kingdom expanded significantly under the rule of Ivan IV, known as Ivan the Terrible, who was crowned as the first Tsar in 1547. The Русское царство continued to grow through military conquests and strategic marriages, influencing the culture, politics, and economy of the region.