Casimir I the Restorer
Around the year 1000, the Roman Catholic Archdiocese of Kraków was created, and its borders covered whole area of Lesser Poland. During the reign of Casimir I the Restorer, Kraków for the first time became the capital of Poland (around 1040), since Greater Poland and Silesia, with main Polish urban centers, such as Gniezno and Poznań were ravaged by Duke Bretislaus I of Bohemia. In 1138, following the Testament of Bolesław III Krzywousty, the country was divided between his sons (see also Fragmentation of Poland). Bolesław III Wrymouth created the Seniorate Province, which, among others, consisted of Kraków. At the same time, Lesser Poland was divided into two parts, when its eastern part formed the Duchy of Sandomierz, carved by the ruler for his son Henry of Sandomierz.