William Herbert, 1st Earl of Pembroke (died 1570)
William Herbert, 1st Earl of Pembroke, 1st Baron Herbert of Cardiff( c. 150117 March 1570) was a Tudor period nobleman, politician, and courtier.
Herbert was the son of Sir Richard Herbert and Margaret Cradock.
His father was an illegitimate son of William Herbert, 1st Earl of Pembroke of the eighth creation( 1468) by his mistress, Maud, daughter of Adam ap Howell Graunt.
Richard Marshal, 3rd Earl of Pembroke
Richard Marshal, 3rd Earl of Pembroke( 119116 April 1234), was the son of William Marshal, 1st Earl of Pembroke and brother of William Marshal, 2nd Earl of Pembroke, whom he succeeded to the Earldom of Pembroke and Lord Marshal of England upon his brother's death on 6 April 1231.
William Herbert, 18th Earl of Pembroke
William Alexander Sidney Herbert, 18th Earl of Pembroke, 15th Earl of Montgomery( born 18 May 1978) is an English peer.
He became earl in 2003 following the death of his father, Henry Herbert, 17th Earl of Pembroke.
Philip Herbert, 7th Earl of Pembroke
Philip Herbert, 7th Earl of Pembroke, 4th Earl of Montgomery KB( 1652/53 – 29 August 1683) was an English nobleman and politician who succeeded to the titles and estates of two earldoms on 8 July 1674 on the death of his brother William Herbert, 6th Earl of Pembroke.
He was a homicidal maniac and convicted murderer, who has been called" the infamous Earl of Pembroke."
Although the murder of the magistrate Sir Edmund Berry Godfrey, which sparked the Popish Plot, has never been solved, a strong body of evidence points to Pembroke as the killer.
Richard Herbert (died 1510)
Sir Richard Herbert Kt( died 1510) of Ewyas, Herefordshire, was an English knight, gentleman, landowner, and courtier.
He was an illegitimate son of William Herbert, 1st Earl of Pembroke, and Maud, a daughter of Adam ap Howell Graunt( Gwynn).
Richard had a full brother named George.
Richard Herbert of Ewyas should not be confused with his uncle, Sir Richard Herbert of Coldbrook, a brother of his father, William Herbert, 1st Earl of Pembroke.
Henry Herbert, 9th Earl of Pembroke
Lt.- Gen. Henry Herbert, 9th Earl of Pembroke, 6th Earl of Montgomery( 29 January 16939 January 1749) was an English peer and courtier.
He was the heir and eldest son of Thomas Herbert, 8th Earl of Pembroke( c. 1656 – 1733) and his first wife Margaret Sawyer.
He was styled Lord Herbert from birth until he inherited his father's earldoms of Pembroke and Montgomery in 1733.
Philip Herbert, 5th Earl of Pembroke
Philip Herbert, 5th Earl of Pembroke, 2nd Earl of Montgomery MP (1621 – 11 December 1669), was an English nobleman and politician.
He was the son of Philip Herbert, 4th Earl of Pembroke, and his first wife Susan de Vere.
He succeeded his father in 1649.
In 1639, he married Penelope Naunton, widow of Paul Bayning, 2nd Viscount Bayning, and daughter of Sir Robert Naunton by his second wife, Penelope Perrot, widow of the astronomer Sir William Lower, and daughter of Sir Thomas Perrot and Dorothy Devereux.
They had one child, William, who succeeded his father as 6th Earl.
In 1649, after the death of his first wife, he married Catherine Villiers, daughter of Sir William Villiers, 1st Baronet.
They had one daughter and two sons, Philip and Thomas.
Both sons later succeeded to their father's titles.
Their daughter, Susan, married John Poulett, 3rd Baron Poulett.
The younger Philip became notorious as "the infamous Earl", due to his frequent bouts of homicidal mania, during which he committed several murders.
He was MP for Wiltshire in 1640 and Glamorgan in 1640–1649.
Henry Herbert, 6th Earl of Carnarvon
Henry George Alfred Marius Victor Francis Herbert, 6th Earl of Carnarvon( 7 November 1898 – 22 September 1987) was a British peer.
He was the son of George Herbert, 5th Earl of Carnarvon and Almina Wombwell, whose biological father was banker Alfred de Rothschild.
William Herbert, 6th Earl of Pembroke
William Herbert, 6th Earl of Pembroke, 3rd Earl of Montgomery MP (c. 1641 – 8 July 1674) was an English nobleman and politician who succeeded to the titles on 11 December 1669 on the death of his father.
Brought up in Wiltshire at Wilton House, he was the son of Philip Herbert, 5th Earl of Pembroke, by his marriage to Penelope Naunton, the daughter of Sir Robert Naunton, Secretary of State to King James I and of Penelope Perrot, a daughter of Sir Thomas Perrot and of Lady Dorothy Devereux (later Countess of Northumberland), whose parents were the famous Earl of Essex and Lettice Knollys.
His mother died before 1647, when he was a small child.
In September 1658, he was granted a pass to travel overseas.
He was member of parliament for Glamorgan between 1661 and his elevation to the House of Lords in 1669.
After he came into his father's great estates, especially in Wiltshire and in Wales, Pembroke was known to exercise a decisive electoral influence in many places.
However, with the Cavalier Parliament enduring from 1661 until 1679, he had few opportunities to wield this influence directly in elections to the House of Commons.
From 1665 to 1674, he was Custos Rotulorum of Wiltshire.
Pembroke died unmarried on 8 July 1674 and was succeeded by his brother, Philip Herbert, 7th Earl of Pembroke, who became known as "the infamous Earl", due to his frequent bouts of homicidal mania.
Mary Woodville
Mary Woodville, Countess of Pembroke( c. 1456–1481) was a sister of Edward IV's Queen consort, Elizabeth Woodville, and of Anthony Woodville, 2nd Earl Rivers.
She later became the first wife of William Herbert, 2nd Earl of Pembroke, by whom she had one daughter.

Question: Who is the paternal grandfather of William Herbert, 6Th Earl Of Pembroke?