sentences:  Łódź, Wrocław and Poznań are each divided into five districts of this type.The word "dzielnica" is also used informally in Polish to refer to any distinct part of a town or city.Historically it can also refer to a region of the country, in particular any of the five principalities into which Poland was divided following the death of Bolesław III Wrymouth in 1138; see Testament of Bolesław III Krzywousty.