Siegfried I, Prince of Anhalt-Zerbst

Siegfried I (c. 1230–1298) was the youngest son of Prince Henry I of Anhalt. In 1247 he joined the War of the Thuringian Succession, but later surrendered his claim to Margrave Henry III of Meissen. When the brothers divided Anhalt in 1252, he became the first Prince of Anhalt-Zerbst, receiving its eastern estates.

In 1273 he stood for the German crown, which instead went to Rudolf of Habsburg. In 1290 he abdicated to enter the Dominican Order, leaving rule to his son Albert I, and died at Köthen Castle in 1298.