He was the third son of Albert I, Prince of Anhalt-Zerbst, but the eldest child born to his second wife Agnes, daughter of Conrad, Margrave of Brandenburg-Stendal.
Still a minor when his father died in 1316, Albert and his younger brother and co-ruler Waldemar I were put under the custody of their maternal uncle, Waldemar, Margrave of Brandenburg-Stendal.
When both brothers were proclaimed adults, they decided to ruled jointly without a territorial division of their inheritance, but with separated residences: Waldemar I decided to live in Dessau and Albert in Zerbst or Köthen.
Together, the brothers acquired full sovereignty over Zerbst, the Margraviate of Landsberg, and the Palatine County of Saxony after the extinction of the Ascanian line of Brandenburg (Frankfurt-am-Main, 27 September 1320), but the Margraviate of Brandenburg was taken by the Emperor Louis IV on behalf of his son.
Her paternal grandmother Agnes of Habsburg was a daughter of Rudolph I, Holy Roman Emperor.