He was the oldest son of Count
Bernhard of Anhalt probably by his first wife Judith (or Jutta) of Poland, a daughter of
Mieszko III the Old. Bernhard was enfeoffed with the
Duchy of Saxony by Emperor
Frederick Barbarossa after the deposition of the
Welf duke
Henry the Lion in 1180. After his death in 1212, his surviving sons divided his lands according to the laws of the House of Ascania: Henry received the old Ascanian
allodial possessions in the Saxon
Schwabengau around
Ballenstedt, where he established the Principality of Anhalt; while his younger brother
Albert inherited the Saxon ducal title and retained several unconnected
Eastphalian estates around the towns of
Wittenberg and
Belzig (later
Saxe-Wittenberg) as well as the northern lordship of
Lauenburg. Henry initially was a loyal supporter of the Hohenstaufen heir
Frederick II, though later he temporarily switched sides to his Welf rival, Emperor
Otto IV, was at feud with the
Archbishops of Magdeburg, and campaigned the estates of
Nienburg Abbey. From about 1215, he began to style himself "prince" (
princeps, ), and by Otto's death in 1218 was officially elevated to that rank attending the
Hoftag diets of Emperor Frederick II. From 1220 Henry acted as a guardian for the minor sons of his Ascanian cousin, the late Margrave
Albert II of Brandenburg, rivalling with both the Magdeburg archbishop
Albert I of Käfernburg and his brother, Duke Albert of Saxony. Henry backed Emperor Frederick II during the rebellion of his son
Henry (VII) in 1234 as well as on his
Italian campaigns against the
Lombard League, participating in the 1238
Siege of Brescia. Back in Germany, he became involved in the conflict between the Magdeburg archbishop
Wilbrand von Käfernburg with his Ascanian cousins, the
Margraves of Brandenburg, whereby the Nienburg estates were devastated by the troops of Margrave
Otto III in 1242. Both sides reconciled in 1245, mediated by Duke
Otto I of Brunswick who married his daughter Matilda, a niece of the Brandenburg margraves, off to Prince Henry's eldest son,
Henry II. Before his death, about 1245, Henry retired and divided the Anhalt principality between his sons: Henry II inherited
Aschersleben, Bernhard received
Bernburg, and Siegfried took
Zerbst. His youngest surviving sons, Hermann and Magnus, were ordained priests. The House of Ascania ruled the
Duchy of Anhalt until 1918. ==Literary patron and poet==