The House of Piast was a royal dynasty that ruled Poland from the 10th to the 14th centuries. It is considered the first historical ruling house of Poland, beginning with Mieszko I, who unified various Slavic tribes and established the Polish state. The dynasty played a crucial role in the Christianization of Poland and the development of its early institutions. The Piast dynasty produced several notable monarchs, including Bolesław I the Brave, who became the first crowned king of Poland. The house eventually declined, leading to the fragmentation of the Polish state and the rise of other dynasties, such as the House of Anjou.