Mieszko I of Poland

Mieszko I (c. 935 – May 25, 992) was a duke of the Polans and the first christian ruler of Poland. He was father of Boleslaw I, first polish king. His politican masterpiece called ,The Baptism of Poland" caused, that germans, bohemians and vielets didn't anymore attacked Poland, beacause he got a baptism from the bishop from the Bohemia, which was a german Fiefdom.
Family.
He was a son of the Siemomysł, the ruler of Polans, and grandson of the Lestek, she was also a father of: Boleslaw I of Poland, the first king of Poland, Mieszko Mieszkowic, Świętosława, the queen of the Vikings and the Granfather of Cnut the Great, the king of the vikings, Mieszko Mieszkowic, Lambert Mieszkowic and Vladivoj - the Duke of Bohemia
Mieszko I (c. 935 – May 25, 992) was a duke of the Polans and the first christian ruler of Poland. He was father of Boleslaw I, first polish king. His politican masterpiece called ,The Baptism of Poland" caused, that germans,bohemians and vielets didn't anymore attacked Poland, beacause he got a baptism from the bishop from the Bohemia, which was a german Fiefdom.
The Politics.
Mieszko was a great politican, an example of his politician and strategist genius was the fact, that he adopted christianity from the Bishop from Bohemia, which was a german fiefdom, and he stopped most of the attacks of Vielets, Bohemians and Germans. He was also a big friend of the Holy Roman Empire's Emperor. He conquered almost all of the terrains of today's Poland and he United all of the Polish tribes in one country, with the capital in Gniezno.
Blindness.
Gallus Anonymus writes that Mieszko was blind until his 7th birthday. That information was used by later chroniclers, but it's probably just an allegory. 
Catholicism.
Mieszko was the first catholic ruler in Poland, he married Dobrawa of Bohemia and after that got baptised.