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.
Fujiwara no Nagara
, also known as Fujiwara no Nagayoshi, was a Japanese statesman, courtier and politician of the early Heian period.
He was the grandfather of Emperor Yōzei.
Abd al-Muttalib
Abd al- Muttalib Shaybah ibn Hashim( c. 497 – 578) was the grandfather of Islamic prophet Muhammad.
Flavia Maximiana Theodora
Flavia Maximiana Theodora, also known as Theodora, was a Roman Empress, wife of Constantius Chlorus.
She is often referred to as a stepdaughter of Emperor Maximian by ancient sources, leading to claims by historians Otto Seeck and Ernest Stein that she was born from an earlier marriage between Eutropia, wife of Maximian, and Afranius Hannibalianus.
This man was consul in 292 and praetorian prefect under Diocletian.
Timothy Barnes challenges this view stating that all "stepdaughter sources" derive their information from the partially unreliable work "Kaisergeschichte" (written in the 4th century), while more reliable sources refer Theodora as Maximian's natural daughter.
He concludes that she was born no later than c. 275 to an unnamed earlier wife of Maximian, possibly one of Hannibalianus' daughters.
In 293, Theodora married Flavius Valerius Julius Constantius (later known as Constantius Chlorus), after he had divorced from his first wife, Helena, to strengthen his political position.
The couple had six children:
Lyon Cohen
Lyon Cohen( 1868–1937) was a Polish- born Canadian businessman and a philanthropist.
He was the grandfather of singer/ poet Leonard Cohen.
John Westley
Rev. John Westley( 1636 – 78) was an English nonconformist minister.
He was the grandfather of John Wesley( founder of Methodism).
Guillaume Wittouck
Guillaume Wittouck( 1749- 1829) was a Belgian lawyer and High Magistrate.
He was the Grandfather of industrialist Paul Wittouck.
Henry Bryant (naturalist)
Henry Bryant( May 12, 1820 – February 2, 1867) was an American physician and naturalist.
He was the grandfather of Henry Bryant Bigelow.
Prithvipati Shah
Prithvipati Shah( ?–1716) was the king of the Gorkha Kingdom in the Indian subcontinent, present- day Nepal.
He was the grandfather of Nara Bhupal Shah.
Flavia Julia Constantia
Flavia Julia Constantia (after 293 – c. 330) was the daughter of the Roman Emperor Constantius Chlorus and his second wife, Flavia Maximiana Theodora.
In 313, Emperor Constantine the Great, who was the half-brother of Constantia, gave her in marriage to his co-emperor Licinius, on occasion of their meeting in Mediolanum.
She bore a son, Valerius Licinianus Licinius, in 315, and when the struggle between Constantine and Licinius began in 316, she stayed on her husband's side.
A second war started between the two emperors in 324; after Licinius' defeat, Constantia interceded with Constantine for her husband's life.
Constantine spared Licinius' life, and obliged him to live in Thessalonica as a private citizen, but the following year (325), he ordered that Licinius be killed.
A second blow for Constantia was the death, also by order of Constantine, of her son Valerius.
In the following years, Constantia lived at her brother's court, receiving honors
(her title was "nobilissima femina").
Constantia was her brother's favourite sister and proof of such favour
is that he minted coins with her image and with the title "Constantia Soror Constantini AVG," or, "Constantia, Sister of Constantine AugustusAVG" is an abbreviation of "Augustus,"
the center consonant being a "manuscript U," not a "V").
She converted to Christianity, supporting the Arian party at the First Council of Nicaea (325).
The city of Constanţa, Romania is named after her.

Question: Who is Flavia Julia Constantia's maternal grandfather?
Answer: Maximian