Boleslav II, the oldest son of Boleslav I and an unknown mother, nephew of Saint Wenceslas. Boleslav II had four sons with several wives: Václav, Boleslav III, Jaromír and Oldřich. His last marriage with Emma, queen-widow of the West German tribes, however was not blessed with a child. After the death of his father Boleslav I in 972 he assumed power in an empire that reached from the Czech forest in the west to what is today western Ukraine. In addition to Bohemia it comprised also northern Moravia, north-western Slovakia, Silesia, part of Poland and Červeňské strongholds. Under his rule, the Prague bishopric began to function. The mintage reached one of its peaks in terms of quantity, as well as quality and artistic value. It was based on the involvement of the Czech lands in international trading, in particular on our participation in the sale of slaves to Islamic countries. His death opened a period of prolonged crisis in Bohemia accompanied by fights among his sons.