Question: Who is Pepin Of Herstal's paternal grandfather?

Context paragraphs:
title: Bernard II, Count of Laon
paragraph_text: Bernard II, Count of Laon(c. 845 – before 893) was a Frankish noble and a member of the Herbertien dynasty, a branch of the Carolingian dynasty. He was a descendant of Pepin of Italy and Charlemagne. He was the first son of Pepin, first count of Vermandois, lord of Senlis, Péronne, and Saint Quentin. In 877/878 he was appointed by Charles the bald. sometime he was go to Parma in Italy, after his life is not known. Bernard II's wife is unknown; Their children were:
title: Nemfidius
paragraph_text: Nemfidius was Patriarch of Provence around 700 CE, during the time of Pepin of Herstal (687-714). He was succeeded by Antenor. Nemfidius issued coins, some of which have reached us.
title: Plectrude
paragraph_text: Plectrude( died 718) was the consort of Pepin of Herstal, the mayor of the palace and duke of the Franks, from about 670. She was the daughter of Hugobert, seneschal of Clovis IV, and Irmina of Oeren. She was the regent of Neustria during the minority of her grandson Theudoald from 714 until 718.
title: Grimoald the Younger
paragraph_text: Grimoald II  (died 714), called the Younger, was the mayor of the palace of Neustria from 695. He was the second son of Pepin of Herstal and Plectrude and his father placed him in the office of mayor of the palace in the Neustrian kingdom in 695, when he was still young. He married Theudesinda (or Theodelinda), daughter of Radbod, King of the Frisians, and had two sons: Theudoald and Arnold. While en route to visit the tomb of Saint Lambert at Liège, he was assassinated by a certain Rangar, in the employ of his father-in-law. His sons carried on a fight to be recognised as Pepin of Herstal's true heirs, since Grimoald predeceased his father and his half-brother Charles Martel usurped the lands and offices of their father. In short, he was innocent but unlucky.
title: Pepin of Herstal
paragraph_text: Pepin II (c. 635 – 16 December 714), commonly known as Pepin of Herstal, was a Frankish statesman and military leader who de facto ruled Francia as the Mayor of the Palace from 680 until his death. He took the title Duke and Prince of the Franks upon his conquest of all the Frankish realms. The son of the powerful Frankish statesman Ansegisel, Pepin worked to establish his family, the Pippinids, as the strongest in Francia. He became Mayor of the Palace in Austrasia in 680. Pepin subsequently embarked on several wars to expand his power. He united all the Frankish realms by the conquests of Neustria and Burgundy in 687. In foreign conflicts, Pepin increased the power of the Franks by his subjugation of the Alemanni, the Frisians, and the Franconians. He also began the process of evangelisation in Germany. Pepin's statesmanship was notable for the further diminution of Merovingian royal authority, and for the acceptance of the undisputed right to rule for his family. Therefore, Pepin was able to name as heir his grandson Theudoald. But this was not accepted by his powerful son Charles Martel, leading to a civil war after his death in which the latter emerged victorious.
title: Grimoald the Elder
paragraph_text: Grimoald I( 616–657), called the Elder( in French," Grimaud l' Ainé"), was the Mayor of the Palace of Austrasia from 640 to 656. He was the son of Pepin of Landen and Itta.
title: Thiadsvind
paragraph_text: Thiadsvind also known as Theudesinda or Theodelinda( 677-?) was the daughter of Redbad, King of the Frisians. In 711 she was married to Grimoald the Younger the eldest son of Pepin of Herstal. The marriage was officiated by archbishop or bishop of the Frisians Willibrord. They had two sons: Theudoald and Arnold.
title: Childebert the Adopted
paragraph_text: Childebert III the Adopted(" Childebertus Adoptivus") was a Frankish king. Childebert was a son of the Mayor of the Palace Grimoald the Elder. He was thus a grandson of Pepin of Landen. He was adopted by King Sigebert III and Queen Chimnechild. When Sigebert III died in 656, Grimoald had Sigebert ’s biological son Dagobert II shorn of hair and sent him to an Irish monastery and then proclaimed Childebert king of Austrasia. Grimoald, Childebert and Ansegisel( who had married the daughter of Pepin of Landen) were finally seized and turned over to the king of Neustria, Clovis II, who had them killed. There are two differing accounts of his death, however. Either Clovis and his mayor of the palace, Erchinoald, captured and executed him in 657 or Chlothar III annexed Austrasia in 661, deposing the young usurper and executing them both the next year. The family reappeared in politics with the rise of Ansegisel ’s son, Pepin of Herstal.
title: Theudoald
paragraph_text: Theudoald( or Theodald; c. 708 – 741) was the mayor of the palace, briefly unopposed in 714 after the death of his grandfather, Pepin of Herstal. Then in 715 the nobility acclaimed Ragenfrid mayor of Neustria and Charles Martel mayor of Austrasia. Theudoald was the legitimate but later claimed illegitimate son of Grimoald II( son of Pepin II of Herstal and Plectrude) and Theudesinda of Frisia( daughter of king Radbod). Thus, he was a grandson of the Frisian king. His grandmother Plectrude tried to have him recognised by his grandfather as the legitimate heir to all the Pippinid lands, instead of Charles Martel. His grandmother surrendered on his behalf in 716 to Chilperic II of Neustria and Ragenfrid. Theudoald died, probably killed, around 741, after the death of his uncle and protector, Charles Martel. It is notable that, despite his having been proclaimed heir to Pepin of Herstal, when Charles Martel seized power, he allowed his nephew to live, instead of killing him, as was often the case in the Middle Ages.
title: Ansegisel
paragraph_text: Ansegisel (c. 602 or 610 – murdered before 679 or 662) was the younger son of Saint Arnulf, bishop of Metz. He served King Sigebert III of Austrasia (634–656) as a duke (Latin "dux", a military leader) and "domesticus". He was killed sometime before 679, slain in a feud by his enemy Gundewin. Through his son Pepin, Ansegisel's descendants would eventually become Frankish kings and rule over the Carolingian Empire.

Reasoning steps:
Pepin of Herstal father Ansegisel
Ansegisel father Arnulf

Answer: spans: Arnulf