Abd al-Muttalib
Abd al- Muttalib Shaybah ibn Hashim( c. 497 – 578) was the grandfather of Islamic prophet Muhammad.
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.
Roman Bagration
Prince Roman (Revaz)
Ivanovich Bagration ("Roman (Revaz) Bagrat'ioni") (1778 – 1834) was a Georgian nobleman and a general in the Imperial Russian Army.
A scion of the Georgian royal family Bagrationi, he was a brother of Pyotr Bagration, a notable Russian commander during the Napoleonic Wars.
Son of Prince Ivan Aleksandrovich Bagration.
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.
Pyotr Romanovich Bagration
Pyotr Romanovich Bagration (24 September 1818 – 17 January 1876), the son of general Prince Roman Bagration, was a Russian-Georgian statesman, general and scientist who invented the first dry galvanic cell.
Guillaume Wittouck
Guillaume Wittouck( 1749- 1829) was a Belgian lawyer and High Magistrate.
He was the Grandfather of industrialist Paul Wittouck.
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.
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.

Question: Who is the paternal grandfather of Pyotr Romanovich Bagration?