Guillaume Wittouck
Guillaume Wittouck( 1749- 1829) was a Belgian lawyer and High Magistrate.
He was the Grandfather of industrialist Paul Wittouck.
John Westley
Rev. John Westley( 1636 – 78) was an English nonconformist minister.
He was the grandfather of John Wesley( founder of Methodism).
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.
Abd al-Muttalib
Abd al- Muttalib Shaybah ibn Hashim( c. 497 – 578) was the grandfather of Islamic prophet Muhammad.
Galla (wife of Theodosius I)
Flavia Galla (died 394) was an empress of the Roman Empire and a princess of the Western Roman Empire.
She was the second empress consort of
Theodosius I. She was the daughter of Valentinian I and his second wife Justina.
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.
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.
Lyon Cohen
Lyon Cohen( 1868–1937) was a Polish- born Canadian businessman and a philanthropist.
He was the grandfather of singer/ poet Leonard Cohen.
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.
Valentinian I
Valentinian I (3 July 32117 November 375), also known as Valentinian the Great, was Roman emperor from 364 to 375.
Upon becoming emperor he made his brother Valens his co-emperor, giving him rule of the eastern provinces while Valentinian retained the west.
During his reign, Valentinian fought successfully against the Alamanni, Quadi, and Sarmatians.
Most notable was his victory over the Alamanni in 367 at the Battle of Solicinium.
His brilliant general Count Theodosius defeated a revolt in Africa and the Great Conspiracy, a coordinated assault on Roman Britain by Picts, Scots, and Saxons.
Valentinian was also the last emperor to conduct campaigns across both the Rhine and Danube rivers.
Valentinian rebuilt and improved the fortifications along the frontiers, even building fortresses in enemy territory.
Due to the successful nature of his reign and the rapid decline of the empire after his death, he is often considered to be the "last great western emperor".
He founded the Valentinian Dynasty, with his sons Gratian and Valentinian II succeeding him in the western half of the empire.

Question: Who is Galla (Wife Of Theodosius I)'s paternal grandfather?
Answer: Gratian