He was the seventh (but fourth surviving) son of Johann, Duke of Saxe-Weimar, and Dorothea Maria of Anhalt.

His regnal name Albert IV derives from the numbering of the duchy of Saxony as a whole, not specifically to the succession in Saxe-Eisenach.

In the years 1619-1621 he completed his Cavalierstour (Study Tour) with his younger brother Johann Frederick.

In Weimar on 24 June 1633 Albrecht married his first cousin Dorothea of Saxe-Altenburg, daughter of Frederick William I, Duke of Saxe-Weimar.

In accordance with a divisionary treaty concluded with his brothers, Albrecht received Eisenach in 1640.