The term "Piast" refers to a historical dynasty that ruled Poland from the 10th to the 14th centuries. The Piast dynasty is significant for establishing the Polish state and its early monarchy. The first ruler of this dynasty was Mieszko I, who united various Slavic tribes and converted to Christianity, which helped integrate Poland into European culture. The Piast dynasty is known for its contributions to the development of Polish law, culture, and society. Notable figures include Bolesław I Chrobry, the first crowned king of Poland, and Casimir III the Great, who is remembered for his reforms and strengthening of the kingdom. The dynasty eventually gave way to the Jagiellonian dynasty in the late 14th century.