Bolesław I the Brave in 1025 he had himself crowned King of Poland. He was the first Polish ruler to receive the title of "rex" (Latin: "king"). He was an able administrator who established the "Prince's Law" and built many forts, churches, monasteries and bridges. He introduced the first Polish monetary unit, the "grzywna", divided into 240 "denarii", and minted his own coinage. Bolesław I is widely considered one of Poland's most capable and accomplished Piast rulers. Bolesław was born in 966 or 967, the first child of Mieszko I of Poland and his wife, the Bohemian princess Dobrawa. His "Epitaph", which was written
Mieszko II Lambert name for his son was an expression of warming relations between Bolesław I and his stepmother Oda. He organized two devastating invasions to Saxony in 1028 and 1030. Then Mieszko II ran a defensive war against Germany, Bohemia and the Kievan princes. Mieszko II was forced to escape from the country in 1031 after an attack of Yaroslav I the Wise, who installed Mieszko's older half-brother Bezprym onto the Polish throne. Mieszko took refuge in Bohemia, where he was imprisoned by the Duke Oldrich. In 1032 he regained power in one of the three districts, then united the country, making