The Piast Dynasty was the first ruling dynasty of Poland, established in the 10th century. It began with Mieszko I, who united various Slavic tribes and converted to Christianity in 966, marking the start of Poland as a recognized state. The dynasty played a crucial role in shaping Polish identity and governance. The Piast Dynasty continued to rule until the late 14th century, with notable figures like Bolesław I the Brave and Casimir III the Great. The dynasty's decline led to the fragmentation of Poland, but its legacy remains significant in Polish history and culture.