Casimir I the Restorer
Wincenty Kadłubek in "Chronica seu originale regum et principum Poloniae" (Chronicles of the Kings and Princes of Poland), written between 1190 and 1208, used the names "Lechitae" (Lechites), "lechiticus" (lechitic) and "Lechia" many times to describe all of medieval Poland. "Chronicle of Greater Poland" 1273 described Casimir I the Restorer as "king of Poles means Lechites". Both the names "Poles" and "Lechites" were used in medieval Poland as adequate terms. "Laesir is the Old Norse term for the Ljachar, a people near the Vistula in Poland". Different forms of the name "Lechia" to designate the Polish state persist in several European languages and in some languages of Central Asia and the Middle East: "Lehia" in Romanian, "Lahestân/لهستان" in Persian (and via borrowing from Persian: "Lehastan" in Armenian, and "Lehistan" in the Ottoman Turkish).