In 1138, a quarrel between the House of Welf and the Hohenstaufers led to the destruction of the castle. It was then the widow’s seat of Eilika Billung of Saxony (~ 1081 to 1142), the mother of Albrecht the Bear (~ 1100 to 1170), who had it rebuilt on the same site. Hailing from the 12th and 13th centuries, the remains of the castle chapel and the imposing keep (“Eulenspiegelturm”) still exist. The “Blue Tower,” the “Old House” and the “Crooked House” date to the Gothic times.
In the 16th century, the castle became one of the most impressive Renaissance palaces of Central Germany. Prince Wolfgang (1492 to 1566), an early confessor of the Reformation, had the western part of the so-called "Langhaus" of Bernburg Castle constructed starting in 1538. The round towers on the western front of the "Langhaus," often referred to as “Leuchten” or “lamps,” and the facade reliefs attached to them are reminders of the work of Renaissance master builder Andreas Günther († 1541). Master builder Nickel Hoffmann (~ 1510 to 1592) completed the “Langhaus” in 1570 with the “Joachim-Ernst-Bau”. At the end of the 17th century, Prince Viktor Amadeus (1634 to 1718) added Baroque elements to the castle: the bridge portal, the Viktor Amadeus Building and the courtyard wall. Further additions from this period include the riding arena with its stables, the orangery and the castle church St. Aegidien.
Since 1858, brown bears inhabit the moat below the castle entrance in an enclosure that was modernized in 1997.