Mieszko I of Poland mentions a gift or dedication of Mieszko's land to the Pope (the act took place almost a hundred years earlier). It is roughly his borders that Poland was returned to in 1945. There is no certain information on Mieszko I's life before he took control over his lands. Only the "Lesser Poland Chronicle" gives the date of his birth as somewhere between the years 920–931 (depending on the version of the manuscript), however, modern researchers don't recognize the Chronicle as a reliable source. Several historians on the basis of their investigations postulated the date of Mieszko I's birth to have
Mieszko I, Duke of Cieszyn the Přemyslid dynasty in the person of Wenceslaus III, son and successor of Wenceslaus II. On 5 October 1305, Mieszko obtained his major victory when his daughter Viola Elisabeth married King Wenceslaus III. This union was a chance for Mieszko to make himself one of the most powerful figures in Bohemia, and he even began some attempts to obtain the Polish crown. However, Mieszko's promising career ended suddenly with the murder of Wenceslaus III (Olomouc, 4 August 1306). Viola Elisabeth never bore Wenceslaus III any children and the Přemyslid dynasty became extinct. After 1306 the political activity of Mieszko almost