Sigismund I, Prince of Anhalt-Dessau
Sigismund I, Prince of Anhalt- Dessau( died Coswig, 19 January 1405), was a German prince of the House of Ascania and ruler of the principality of Anhalt- Zerbst until 1396, when he became the first ruler of the principality of Anhalt- Dessau.
He was the eldest son of John II, Prince of Anhalt- Zerbst, by his wife Elisabeth, daughter of John I, Count of Henneberg- Schleusingen.
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.
Otto I, Prince of Anhalt-Aschersleben
Otto I, Prince of Anhalt-Aschersleben (died 25 June 1304) was a German prince of the House of Ascania and ruler of the principality of Anhalt-Aschersleben.
He was the eldest son of Henry II, Prince of Anhalt-Aschersleben, by his wife Matilda, daughter of Otto the Child, Duke of Brunswick-Lüneburg.
Otto was named after his maternal grandfather.
Otto II, Prince of Anhalt-Aschersleben
Otto II, Prince of Anhalt- Aschersleben( died 24 July 1315) was a German prince of the House of Ascania and the last ruler of the principality of Anhalt- Aschersleben.
He was the last child and only son of Otto I, Prince of Anhalt- Aschersleben, by his wife Hedwig, daughter of Henry III the White, Duke of Breslau.
Henry III, Prince of Anhalt-Aschersleben
Henry III, Prince of Anhalt- Aschersleben( died 9 November 1307) was a German prince of the House of Ascania and ruler of the principality of Anhalt- Aschersleben.
He was the youngest son of Henry II, Prince of Anhalt- Aschersleben, by his wife Matilda, daughter of Otto the Child, Duke of Brunswick- Lüneburg.
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 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.
Albert IV, Prince of Anhalt-Köthen
Albert IV, Prince of Anhalt- Köthen( d. Coswig, 24 November 1423), was a German prince of the House of Ascania and ruler of the principality of Anhalt- Zerbst until 1396, when he became the first ruler of the principality of Anhalt- Köthen.
He was the second son of John II, Prince of Anhalt- Zerbst, by his wife Elisabeth, daughter of John I, Count of Henneberg- Schleusingen.
Henry II, Prince of Anhalt-Aschersleben
Henry II, Prince of Anhalt-Aschersleben (1215 – 12 June 1266) was a German prince of the House of Ascania and ruler of the principality of Anhalt-Aschersleben.
He was the eldest son of Henry I, Count of Anhalt (who was raised to the rank of prince in 1218), by his wife Irmgard, daughter of Hermann I, Landgrave of Thuringia.
Christian I, Prince of Anhalt-Bernburg
Christian I, Prince of Anhalt-Bernburg, also known as Christian of Anhalt, (11 May 1568 – 17 April 1630) was a German prince of the House of Ascania.
He was ruling prince of Anhalt and, from 1603, ruling prince of the revived principality of Anhalt-Bernburg.
From 1595 he was governor of Upper Palatinate, and soon became the advisor-in-chief of Frederick IV, Elector Palatine.

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