Albert's entanglements in Saxony stemmed from his desire to expand his inherited estates there. After the death of his brother-in-law, Henry II, margrave of a small area on the Elbe called the Saxon Northern March, in 1128, Albert, disappointed at not receiving this fief himself, attacked Udo, the heir, and was consequently deprived of Lusatia by Lothar. In spite of this, he went to Italy in 1132 in the train of the king, and his services there were rewarded in 1134 by the investiture of the Northern March, which was again without a ruler.
Once he was firmly established in the Northern March, Albert's covetous eye lay also on the thinly populated lands to the north and east. Three years he was occupied in campaigns against the Slavic Wends, who as pagans were considered fair game, and whose subjugation to Christianity was the aim of the Wendish Crusade of 1147 in which Albert took part; diplomatic measures were more successful, and by an arrangement made with the last of the Wendish princes of Brandenburg, Pribislav of the Hevelli, Albert secured this district when the prince died in 1150. Taking the title "Margrave of Brandenburg", he pressed the "crusade" against the Wends, extended the area of his mark, encouraged German migration, established bishoprics under his protection, and so became the founder of the Margraviate of Brandenburg in 1157, which his heirs — the House of Ascania — held until the line died out in 1320.
In 1137 Conrad III, the Hohenstaufen King of the Germans, deprived Albert's cousin and nemesis, Henry the Proud of his Saxon duchy, which was awarded to Albert if he could take it. After some initial success in his efforts to take possession, Albert was driven from Saxony, and also from his Northern march by Henry, and compelled to take refuge in south Germany. When peace was made with Henry in 1142, Albert renounced the Saxon duchyand received the Counties of Weimar and Orlamünde. It was possibly at this time that Albert was made Arch-Chamberlain of the Empire, an office which afterwards gave the Margraves of Brandenburg the rights of a prince-elector.
In 1158 a feud with Henry's son, Henry the Lion, Duke of Saxony, was interrupted by a pilgrimage to the Holy Land. In 1162 Albert accompanied Emperor Frederick Barbarossa to Italy, where he distinguished himself at the storming of Milan.
In 1164 Albert joined a league of princes formed against Henry the Lion, and peace being made in 1169, Albert divided his territories among his six sons. He died on 13 November 1170, possibly in Stendal, and was buried at Ballenstedt.
Albert was married in 1124 to Sofie of Winzenburg (died 25 March 1160) and they had the following children: