Mieszko I, Duke of Cieszyn Mieszko I, Duke of Cieszyn Mieszko I of Cieszyn (, , ; also known as Mieszko I of Opole; 1252/56 – by 27 June 1315), was a Duke of Racibórz during 1282–1290 (with his brother as co-ruler) and the first Duke of Cieszyn since 1290 until his death. He was the oldest son of Władysław, Duke of Opole-Racibórz, by his wife Euphemia, daughter of Władysław Odonic, Duke of Greater Poland. Little is known about the early years of Mieszko I's life. His first documented mention was on 21 October 1258, when he appears together with his father and two younger
Bolesław the Forgotten calendar was in use so New Year's Day had not been changed to the first day of January. The text describes him as follows: However, there is no mention of any coronation of a Polish ruler in this period, which would have to be recorded in the German sources (as was the case with the coronations of Bolesław I and Mieszko II), probably because there was no royal insignia in the country, which had been returned to the Emperor by the well-known Bezprym earlier in the year 1031. This brief description of Bolesław in the "Wielkopolska Chronicle" is very similar