 Complete the following phrase:  Albert was the only son of Otto, Count of Ballenstedt, and Eilika, daughter of Magnus Billung, Duke of Saxony. He inherited his fathers valuable estates in northern Saxony in 1123, and on his mothers death, in 1142, succeeded to one-half of the lands of the house of Billung. Albert was a loyal vassal of his relation, Lothar I, Duke of Saxony, from whom, about 1123, he received the Margraviate of Lusatia, to the east; after Lothar became King of the Germans, he accompanied him on a disastrous expedition to Bohemia against the upstart, Soběslav I, Duke of Bohemia in 1126 at the 