Question: Who is the paternal grandfather of Alexios Komnenos (Son Of Andronikos I)?

Knowledge 1: Alexios Komnenos (son of Andronikos I)
Alexios Komnenos (1170 – 1199) was a natural son of Andronikos I Komnenos, the Byzantine Emperor(r. 1183 – 1185) by his relative and mistress Theodora Komnene, Queen Dowager of Jerusalem.During the reign of Emperor Manuel I Komnenos (r. 1143–1180), Alexios accompanied his father Andronikos in exile, visiting, inter alia, the Kingdom of Georgia.The Georgian king George III, their relative, granted to Andronikos several castles in Kakhetia in the east of Georgia.Andronikos returned to Constantinople and attained to the Byzantine crown in 1183, only to be overthrown and killed in 1185.Alexios then fled to Georgia, where he was restored to his father's Georgian estates.At one point, he was even considered by some Georgian nobles as a candidate to become a consort of the queen regnant Tamar of Georgia.According to the Georgian historical tradition, Alexios's progeny flourished in Georgia, producing the noble family of Andronikashvili, i.e., "scions of Andronikos", so named after Alexios's purported son.In spite of the extremely fragmentary nature of the early Andronikashvili pedigree, Professor Cyril Toumanoff (1976) accepted the Komnenian origin as plausible, but the evidence marshaled by Kuršankis (1977) suggests that this may have been only a legend.Toumanoff also assumed that the line of the "provincial kings" of Alastani (c. 1230–1348), known from the medieval Georgian sources and including one named Andronikos, might have belonged to the Georgian Komnenoi/Andronikashvili. [SEP] Knowledge 2: Andronikos I Komnenos
Andronikos I Komnenos (– 12 September 1185), usually Latinized as Andronicus I Comnenus, was Byzantine Emperor from 1183 to 1185.He was the son of Isaac Komnenos and the grandson of the emperorAlexios I.
Knowledge 1: Alexios Komnenos (son of Andronikos I)
Alexios Komnenos (1170 – 1199) was a natural son of Andronikos I Komnenos, the Byzantine Emperor(r. 1183 – 1185) by his relative and mistress Theodora Komnene, Queen Dowager of Jerusalem.During the reign of Emperor Manuel I Komnenos (r. 1143–1180), Alexios accompanied his father Andronikos in exile, visiting, inter alia, the Kingdom of Georgia.The Georgian king George III, their relative, granted to Andronikos several castles in Kakhetia in the east of Georgia.Andronikos returned to Constantinople and attained to the Byzantine crown in 1183, only to be overthrown and killed in 1185.Alexios then fled to Georgia, where he was restored to his father's Georgian estates.At one point, he was even considered by some Georgian nobles as a candidate to become a consort of the queen regnant Tamar of Georgia.According to the Georgian historical tradition, Alexios's progeny flourished in Georgia, producing the noble family of Andronikashvili, i.e., "scions of Andronikos", so named after Alexios's purported son.In spite of the extremely fragmentary nature of the early Andronikashvili pedigree, Professor Cyril Toumanoff (1976) accepted the Komnenian origin as plausible, but the evidence marshaled by Kuršankis (1977) suggests that this may have been only a legend.Toumanoff also assumed that the line of the "provincial kings" of Alastani (c. 1230–1348), known from the medieval Georgian sources and including one named Andronikos, might have belonged to the Georgian Komnenoi/Andronikashvili. [SEP] Knowledge 2: George Palaiologos
George (Georgios) Palaiologos or Palaeologus  was a Byzantine general, one of the most prominent military commanders and supporters of Emperor Alexios I Komnenos (r. 1081–1118).He was the son of the first known member of the Palaiologos family, the "strategos" of Mesopotamia Nikephoros Palaiologos.His wife Anna Doukaina was the sister of Irene Doukaina, the wife of Alexios I Komnenos, making him the emperor's brother-in-law.As Alexios Komnenos’ leading general and close friend, he played an important role in his campaigns, especially the Battle of Dyrrhachium against the Normans or the Battle of Levounion against the Pechenegs.He was the chief source used by Anna Komnene in her "Alexiad" on her father’s battles, and is very favourably portrayed by her in her book as both capable and loyal.
Knowledge 1: Alexios Komnenos (son of Andronikos I)
Alexios Komnenos (1170 – 1199) was a natural son of Andronikos I Komnenos, the Byzantine Emperor(r. 1183 – 1185) by his relative and mistress Theodora Komnene, Queen Dowager of Jerusalem.During the reign of Emperor Manuel I Komnenos (r. 1143–1180), Alexios accompanied his father Andronikos in exile, visiting, inter alia, the Kingdom of Georgia.The Georgian king George III, their relative, granted to Andronikos several castles in Kakhetia in the east of Georgia.Andronikos returned to Constantinople and attained to the Byzantine crown in 1183, only to be overthrown and killed in 1185.Alexios then fled to Georgia, where he was restored to his father's Georgian estates.At one point, he was even considered by some Georgian nobles as a candidate to become a consort of the queen regnant Tamar of Georgia.According to the Georgian historical tradition, Alexios's progeny flourished in Georgia, producing the noble family of Andronikashvili, i.e., "scions of Andronikos", so named after Alexios's purported son.In spite of the extremely fragmentary nature of the early Andronikashvili pedigree, Professor Cyril Toumanoff (1976) accepted the Komnenian origin as plausible, but the evidence marshaled by Kuršankis (1977) suggests that this may have been only a legend.Toumanoff also assumed that the line of the "provincial kings" of Alastani (c. 1230–1348), known from the medieval Georgian sources and including one named Andronikos, might have belonged to the Georgian Komnenoi/Andronikashvili. [SEP] Knowledge 2: Jiajak Jaqeli
Jiajak Jaqeli was the Empress consort of Alexios II of Trebizond.

Answer: Isaac Komnenos