Ferdinand Maximilien Mériadec de Rohan
Ferdinand Maximilien Mériadec de Rohan( 1738–1813) was an Archbishop of Bordeaux starting in 1769, and Prince- Archbishop of Cambrai from 1781.
He was the son of Hercule Meriadec de Rohan, prince de Guéméné and Louise- Gabrielle Julie de Rohan; brother of cardinal de Rohan, and Jules, prince de Guéméné.
Mériadec was a chaplain of the Empress Joséphine de Beauharnais.
He served as prior and doctor of the Sorbonne and provost of the church of Strasbourg.
He was nominated Archbishop of Bordeaux by King Louis XV on 26 December 1769, and his bulls were granted by Pope Clement XIV in the Consistory of 29 January 1770.
He was consecrated a bishop in the church of the Sorbonne on 8 April 1770 by his brother Louis, the coadjutor Archbishop of Strasbourg, assisted by the Bishops of Poitiers and Vabres.
He was installed in Bordeaux by procurator.
He made his solemn entry into Bordeaux on 5 May 1771.
He was nominated Archbishop of Cambrai by King Louis XVI on 28 January 1781, and received his bulls from Pope Pius VI dated 2 April 1781.
He died in Paris in 1813.
His mistress was Charlotte Stuart, Duchess of Albany, illegitimate daughter of Prince Charles Edward Stuart, with whom he had three children, including Charles Edward Stuart, Count Roehenstart.
Lacking legitimacy or permission, Charlotte was unable to marry.
Thus, she otherwise sought a protector and provider.
Probably unbeknownst to her father, Prince Charles Edward Stuart(" Bonnie Prince Charlie"), she became the mistress of Mériadec – related by blood to the house of Stuart as well as Bourbon and Lorraine – who was also unable to marry legitimately, having entered the Church as a younger son of a noble house.
By him, she had three children: two daughters, Marie Victoire and Charlotte, and finally a son, Charles Edward.
Her children were kept secret, and remained largely unknown until the 20th century.
When Charlotte eventually left France for Florence shortly after her son's birth, she entrusted the children into the care of her mother, Clementina Walkinshaw, and it appears that few, and certainly not her father, knew of their existence.
His sister- in- law, Marie Louise de La Tour d'Auvergne, was a first cousin of Prince Charles Edward Stuart and became his mistress.
They had a son together, Charles Godefroi Sophie Jules Marie de Rohan, but Charles left her for Clementina Walkinshaw, with whom he had Charlotte.
Maria Clementina Sobieska
Maria Clementina Sobieska( 18 July 1702 – 18 January 1735) was a Titular Queen consort of England by marriage to James Francis Edward Stuart, a Jacobite claimant to the British throne.
The granddaughter of the Polish king John III Sobieski, she was the mother of Charles Edward Stuart and of Cardinal Henry Benedict Stuart.
Countess Palatine Hedwig Elisabeth of Neuburg
Hedwig Elisabeth of Neuburg (Hedwig Elisabeth Amelia; 18 July 1673 – 10 August 1722) was a Polish princess by marriage to James Louis Sobieski.
She was the daughter of Philip William, Duke of Neuburg, Berg and Jülich, Elector Palatine of Neuburg, and Landgravine Elisabeth Amalie of Hesse-Darmstadt.
She was the grandmother of Charles Edward Stuart, the "Young Pretender".
John Stuart, Count of Maida
Sir John Stuart, Count of Maida (1759 – 2 April 1815) was a British Lieutenant-General during the Napoleonic Wars.
Charles E. Stuart
Charles Edward Stuart( November 25, 1810 May 19, 1887) was a U.S. Representative and U.S. Senator from the state of Michigan.
Hannah Arnold
Hannah Arnold, also known as Hannah Waterman King, was the grandmother of Benedict Arnolds children.
Tjuyu
Tjuyu( sometimes transliterated as Thuya or Thuyu) was an Egyptian noblewoman and the mother of queen Tiye, and the wife of Yuya.
She is the grandmother of Akhenaten, and great grandmother of Tutankhamun.
Charlotte Stuart, Duchess of Albany
Charlotte Stuart, styled Duchess of Albany (29 October 1753 – 17 November 1789) was the illegitimate daughter of the Jacobite pretender Prince Charles Edward Stuart ('Bonnie Prince Charlie' or the 'Young Pretender') and his only child to survive infancy.
Her mother was Clementina Walkinshaw, who was mistress to the Prince from 1752 until 1760.
After years of abuse, Clementina left him, taking Charlotte with her.
Charlotte spent most of her life in French convents, estranged from a father who refused to make any provision for her.
Unable to marry, she herself became a mistress with illegitimate children, taking Ferdinand de Rohan, Archbishop of Bordeaux, as her lover.
She was finally reconciled with her father in 1784, when he legitimised her and created her Duchess of Albany in the Jacobite Peerage.
She left her own children with her mother, and became her father's carer and companion in the last years of his life, before dying less than two years after him.
Her three children were raised in anonymity; however, as the only grandchildren of the pretender, they have been the subject of Jacobite interest since their lineage was uncovered in the 20th century.
Hubba bint Hulail
Hubba bint Hulail was the grandmother of Hashim ibn' Abd Manaf, thus the great- great- great- grandmother of the Islamic" Nabī"( Prophet) Muhammad ibn Abdullah.
Charles Edward Stuart, Count Roehenstart
Charles Edward Augustus Maximilian Stuart, Baron Korff, Count Roehenstart (– 28 October 1854) was the natural son of Prince Ferdinand of Rohan (1738–1813), Roman Catholic Archbishop of Cambrai, by Charlotte Stuart, Duchess of Albany, herself the natural but legitimised daughter of Charles Edward Stuart, "The Young Pretender" or "Bonnie Prince Charlie".
Roehenstart was later a passive Jacobite claimant to the British throne.
The name of "Roehenstart" given to him in infancy combined the names of both of his parents, Rohan and Stuart, while failing to proclaim their identity, which at the time would have been a cause for scandal.
Although he retired from military service as a lieutenant colonel, he is sometimes called "General" Charles Edward Stuart, and this title appears on his gravestone at Dunkeld.

Question: Who is the maternal grandmother of Charles Edward Stuart, Count Roehenstart?
Answer: Clementina Walkinshaw