Казимир I
Greater Poland formed the heart of the 10th-century early Polish state, sometimes being called the "cradle of Poland". Poznań and Gniezno were early centres of royal power, but following devastation of the region by pagan rebellion in the 1030s, and the invasion of Bretislaus I of Bohemia in 1038, the capital was moved by Casimir I the Restorer from Gniezno to Kraków.