Question: Who is the maternal grandfather of Eysteinn?

Knowledge 1: Eysteinn
Eysteinn (Swedish: Östen; died ca 600) was the son of Eadgils and Yrsa of Saxony.He was the father of Ingvar.The Eysteinn tumulus "(Östens hög)" in Västerås near Östanbro has been linked to King Eysteinn by some popular historians.The term Hög is derived from the Old Norse word "haugr" meaning mound or barrow.Eysteinn ruled Sweden at the time when Hrólf Kraki died in Lejre.It was a troubled time when many sea kings ravaged Swedish shores.One of those kings was named Sölve and he was from Jutland (but according to "Historia Norwegiae" he was Geatish, see below).At this time Sölve was pillaging in the Baltic Sea.He arrived in Lofond (probably the island of Lovön or the Lagunda Hundred), where Eysteinn was at a feast.Sölve and his men surrounded the house and set it on fire burning everyone inside to death.Then Sölve arrived at Sigtuna (Old Sigtuna) and ordered the Swedes to accept him as king.The Swedes refused and gathered an army that fought against Sölve and his men, but they lost after eleven days.The Swedes had to accept him as king until they rebelled and killed him. [SEP] Knowledge 2: Yrsa
Yrsa, "YrseYrs" or "Urse" (6th century) was a tragic heroine of early Scandinavian literature.She appears in several versions relating to her husband, the Swedish king Eadgils, and/or to her father and rapist/lover/husband Halga (the younger brother of king Hroðgar who received Beowulf) and their son Hroðulf.The common claim in "Beowulf" studies that Hroðulf probably was the son of Halga is taken from the Yrsa tradition.Several translators (e.g. Burton Raffel) and scholars have emended her name from a corrupt line (62) in the manuscript of "Beowulf", although this is guesswork.In the "Ynglinga saga", Snorri Sturluson describes her personality as follows(Samuel Laing's translation):Yrsa was not one of the slave girls, and it was soon observed that she was intelligent, spoke well, and in all respects was well behaved.All people thought well of her, and particularly the king; and at last it came to so far that the king celebrated his wedding with her, and Yrsa became queen of Svithiod, and was considered an excellent woman.
Knowledge 1: Eysteinn
Eysteinn (Swedish: Östen; died ca 600) was the son of Eadgils and Yrsa of Saxony.He was the father of Ingvar.The Eysteinn tumulus "(Östens hög)" in Västerås near Östanbro has been linked to King Eysteinn by some popular historians.The term Hög is derived from the Old Norse word "haugr" meaning mound or barrow.Eysteinn ruled Sweden at the time when Hrólf Kraki died in Lejre.It was a troubled time when many sea kings ravaged Swedish shores.One of those kings was named Sölve and he was from Jutland (but according to "Historia Norwegiae" he was Geatish, see below).At this time Sölve was pillaging in the Baltic Sea.He arrived in Lofond (probably the island of Lovön or the Lagunda Hundred), where Eysteinn was at a feast.Sölve and his men surrounded the house and set it on fire burning everyone inside to death.Then Sölve arrived at Sigtuna (Old Sigtuna) and ordered the Swedes to accept him as king.The Swedes refused and gathered an army that fought against Sölve and his men, but they lost after eleven days.The Swedes had to accept him as king until they rebelled and killed him. [SEP] Knowledge 2: Kaya Alp
Kaya Alp was, according to Ottoman tradition, the son of Kızıl Buğa and the father of Suleyman Shah, who was, in turn, the grandfather of Ertuğrul, and the great grandfather of the Ottoman Empire founder, Osman I.
Knowledge 1: Eysteinn
Eysteinn (Swedish: Östen; died ca 600) was the son of Eadgils and Yrsa of Saxony.He was the father of Ingvar.The Eysteinn tumulus "(Östens hög)" in Västerås near Östanbro has been linked to King Eysteinn by some popular historians.The term Hög is derived from the Old Norse word "haugr" meaning mound or barrow.Eysteinn ruled Sweden at the time when Hrólf Kraki died in Lejre.It was a troubled time when many sea kings ravaged Swedish shores.One of those kings was named Sölve and he was from Jutland (but according to "Historia Norwegiae" he was Geatish, see below).At this time Sölve was pillaging in the Baltic Sea.He arrived in Lofond (probably the island of Lovön or the Lagunda Hundred), where Eysteinn was at a feast.Sölve and his men surrounded the house and set it on fire burning everyone inside to death.Then Sölve arrived at Sigtuna (Old Sigtuna) and ordered the Swedes to accept him as king.The Swedes refused and gathered an army that fought against Sölve and his men, but they lost after eleven days.The Swedes had to accept him as king until they rebelled and killed him. [SEP] Knowledge 2: Abd al-Muttalib
Abd al- Muttalib Shaybah ibn Hashim( c. 497 – 578) was the grandfather of Islamic prophet Muhammad.

Answer: Halga