Poland began to form into a recognisable unitary and territorial entity around the middle of the 10th century under the Piast dynasty. In 966 AD, Duke Mieszko I accepted Christianity as the rightful religion under the auspices of the Latin Church with the Baptism of Poland. An incipit titled Dagome iudex first defined Poland’s geographical boundaries with capital at Gniezno and affirmed that its monarchy was under the protection of the Apostolic See.