Siegfried was the youngest son of Prince
Henry I of Anhalt by his wife Irmgard, daughter of the
Ludovingian landgrave
Hermann I of Thuringia. His father had received the
Anhalt territory upon the death of Duke
Bernhard III of Saxony in 1212 and was raised to the rank of a
Prince of the Holy Roman Empire six years later. In 1247, after the death of the Thuringian landgrave
Henry Raspe, younger brother of his mother Irmgard and last male heir of the Ludovinger dynasty, Siegfried interfered in the succeeding
War of the Thuringen Succession. During the conflict, the young prince occupied the
County palatine (German:
Pfalzgrafschaft), by right of his mother. Later he renounced the county in favor of the
Wettin margrave
Henry III of Meissen in exchange for a monetary compensation. After the death of his father in 1252, in accordance with the family law of the Ascanian dynasty, Siefgried and his elder brothers
Henry II and
Bernhard divided the Anhalt lands. Siegfried received the eastern estates around
Köthen. His style
Count of Köthen-Dessau (used from 1253) likewise derived from the territories he received as his inheritance. In 1273 he even stood as a candidate in the
Imperial election, though the princes eventually elected Count
Rudolf of Habsburg king. In 1290 Siegfried renounced his rule to become a preaching monk (German:
Predigermönch). As a result, his eldest son Prince
Albert I of Anhalt became the actual ruler in the Köthen and
Zerbst estates, although the former prince retained his rank until his death. Siegfried died at
Köthen Castle in 1298. ==Marriage and issue==