Alexius Frederick Christian, Duke of Anhalt-Bernburg
Alexius Frederick Christian of Anhalt- Bernburg( 12 June 1767 – 24 March 1834), was a German prince of the House of Ascania.
From 1796 until 1807 he was Reigning prince of the principality of Anhalt- Bernburg, and from 1807 until 1834 the first Duke of the Duchy of Anhalt- Bernburg.
John I, Prince of Anhalt-Bernburg
John I, Prince of Anhalt- Bernburg( died 5 June 1291) was a German prince of the House of Ascania and ruler of the principality of Anhalt- Bernburg.
He was the eldest son of Bernhard I, Prince of Anhalt- Bernburg, by his wife Princess Sophie, daughter of King Abel of Denmark.
Bernhard II, Prince of Anhalt-Bernburg
Bernhard II, Prince of Anhalt- Bernburg( ca. 1260 – aft. 26 December 1323), was a German prince of the House of Ascania and ruler of the principality of Anhalt- Bernburg.
He was the third son of Bernhard I, Prince of Anhalt- Bernburg, by his wife Princess Sophie, daughter of King Abel of Denmark.
Bernhard VI, Prince of Anhalt-Bernburg
Bernhard VI, Prince of Anhalt- Bernburg( died 2 February 1468) was a German prince of the House of Ascania and ruler of the Principality of Anhalt- Bernburg.
He was the eldest son of Otto III, Prince of Anhalt- Bernburg, by his first unknown wife.
Bernhard IV, Prince of Anhalt-Bernburg
Bernhard IV, Prince of Anhalt- Bernburg( died 28 June 1354) was a German prince of the House of Ascania and ruler of the principality of Anhalt- Bernburg.
He was the eldest son of Bernhard III, Prince of Anhalt- Bernburg, by his first wife Agnes, daughter of Rudolf I, Duke of Saxe- Wittenberg and Elector of Saxony.
Bernhard III, Prince of Anhalt-Bernburg
Bernhard III, Prince of Anhalt- Bernburg( died 20 August 1348) was a German prince of the House of Ascania and ruler of the principality of Anhalt- Bernburg.
He was the eldest son of Bernhard II, Prince of Anhalt- Bernburg, by his wife Helene, daughter of Wizlaw II, Prince of Rügen.
Otto III, Prince of Anhalt-Bernburg
Otto III, Prince of Anhalt-Bernburg (died 27 February 1404) was a German prince of the House of Ascania and ruler of the principality of Anhalt-Bernburg.
He was the youngest son of Bernhard III, Prince of Anhalt-Bernburg, by his third wife Matilda, daughter of Magnus I, Duke of Brunswick-Göttingen.
Otto IV, Prince of Anhalt-Bernburg
Otto IV, Prince of Anhalt-Bernburg (died 1 May 1415) was a German prince of the House of Ascania and ruler of the principality of Anhalt-Bernburg.
He was the youngest son of Otto III, Prince of Anhalt-Bernburg, by his unknown first wife.
Henry IV, Prince of Anhalt-Bernburg
Henry IV, Prince of Anhalt- Bernburg( died 7 July 1374) was a German prince of the House of Ascania and ruler of the principality of Anhalt- Bernburg.
He was the second son of Bernhard III, Prince of Anhalt- Bernburg, by his first wife Agnes, daughter of Rudolf I, Duke of Saxe- Wittenberg.
Bernhard V, Prince of Anhalt-Bernburg
Bernhard V, Prince of Anhalt- Bernburg( died 24 June 1420) was a German prince of the House of Ascania and ruler of the principality of Anhalt- Bernburg.
He was the eldest son of Henry IV, Prince of Anhalt- Bernburg, by his wife Sophie, a possible member of the House of Stolberg.

Question: Who is the paternal grandfather of Otto Iv, Prince Of Anhalt-Bernburg?