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 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.
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.
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.
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.
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 I, Prince of Anhalt-Bernburg
Bernhard I, Prince of Anhalt-Bernburg (c. 1218–1287) was a German prince of the House of Ascania and ruler of the principality of Anhalt-Bernburg.
He was the second son of Henry I, Count of Anhalt (who was elevated to the rank of prince in 1218), by his wife Irmgard, daughter of Hermann I, Landgrave of Thuringia.
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.

Question: Who is John I, Prince Of Anhalt-Bernburg's paternal grandfather?
Answer: Henry I, Count of Anhalt