Mieszko I, Duke of Cieszyn and 1280. They had three children: 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
Mieszko I of Poland situation at that time. Another debatable point is Thietmar's claim that Mieszko "subordinated himself to the King". Most historians believe that it was only a matter of recognition of Otto's royal authority. Some suggest that a fealty relationship could in fact be involved. Whether or not the German-Polish invasion of Bohemia actually happened, the friendly relations between the Czechs and the Poles came to an end. Bohemia resumed its earlier alliance with the Lutici, which caused in 990 a war with Mieszko, who was supported by Empress Theophanu. Duke Boleslav II was probably the first one to attack. As a