Christian August was the third son of John Louis I, Prince of Anhalt-Dornburg and Christine Eleonore of Zeutsch (1666–1699).

In 1711, Christian August was awarded the Order De la Générosité, later renamed in Pour le Mérite, and on 1 March 1713 was elevated to the rank of lieutenant-colonel.

On 16 May 1742 Prussian King Frederick the Great awarded him the highest military dignity, the rank of Generalfeldmarschall.

Christian August remained in Stettin and his brother took full charge of the government, but he died only four years later, unmarried and childless.

For this reason, Christian August had to leave Stettin and return to Zerbst, but he only reigned four months until his own death.