History of Poland during the Piast dynasty of Lesser Poland, the country of the Vistulans, and of Silesia (both taken by Mieszko from the Czech state during the later part of the 10th century), Mieszko's state reached its mature form, including the main regions regarded as ethnically Polish. The Piast lands totaled about in area, with an approximate population of under one million. Initially a pagan, Mieszko I was the first ruler of the Polans tribal union known from contemporary written sources. A detailed account of aspects of Mieszko's early reign was given by Ibrâhîm ibn Ya`qûb, a Jewish traveler, according to whom Mieszko was one of
Mieszko I of Poland in the hands of Bohemia. Sandomierz under this scenario was the central hub of the area, with Czerwień, Przemyśl and Chełm assuming the function of defensive borderland strongholds. After the death of Emperor Otto I in 973 Mieszko, like his brother-in-law, Duke Boleslav II of Bohemia, joined the German opposition in support of the attempted imperial succession of Henry II, Duke of Bavaria. Mieszko may have been motivated by revenge because of the (presumably) negative verdict of the Quedlinburg summit, but, more importantly, he may have wanted more favorable terms for his cooperation with Germany. The participation of Mieszko in