Louis Philippe I
Louis Philippe I( 6 October 1773 – 26 August 1850) was King of the French from 1830 to 1848.
As Duke of Chartres he distinguished himself commanding troops during the Revolutionary Wars but broke with the Republic over its decision to execute King Louis XVI.
He fled to Switzerland in 1793 after being connected with a plot to restore France's monarchy.
His father Louis Philippe II, Duke of Orléans( Philippe Égalité) fell under suspicion and was executed, and Louis Philippe remained in exile for 21 years until the Bourbon Restoration.
He was proclaimed king in 1830 after his cousin Charles X was forced to abdicate by the July Revolution.
The reign of Louis Philippe is known as the July Monarchy and was dominated by wealthy industrialists and bankers.
He followed conservative policies, especially under the influence of French statesman François Guizot during the period 1840 – 48.
He also promoted friendship with Britain and sponsored colonial expansion, notably the French conquest of Algeria.
His popularity faded as economic conditions in France deteriorated in 1847, and he was forced to abdicate after the outbreak of the French Revolution of 1848.
He lived out his life in exile in the United Kingdom.
His supporters were known as Orléanists, as opposed to Legitimists who supported the main line of the House of Bourbon.
Sébastien, Duke of Penthièvre
Sebastien de Luxembourg, duke of Penthièvre( 1530- 1569) was vicount of Martigues, count and later duke of Penthièvre( 1566 – 1569) and a peer of France.
He was the son of François de Luxembourg and Charlotte de Brosse, daughter of René de Brosse.
Nephew of Jean de Brosse, duc d'Étampes, he was allowed to inherit his uncle's taken estates and was subsequently created the 1st Duke of Penthièvre.
He participated at the Siege of Leith in 1560, but was killed on November 19 1569 at the Siege of Saint- Jean- d'Angely .<br>
His only daughter and heiress Marie de Luxembourg married Philippe- Emmanuel de Lorraine, duc de Mercœur, the rebel in Brittany.
Constance of Penthièvre
Constance of Penthièvre( c. 1140 – after 23 June 1184) was a Breton princess, daughter of Alan of Penthièvre, 1st Earl of Richmond, and Bertha of Cornouaille," suo jure" Duchess of Brittany.
Philippe Charles, Duke of Valois
Philippe Charles d'Orléans, "petit-fils de France", Duke of Valois (16 July 1664 – 8 December 1666) was a French prince and "Grandson of France".
He was styled Duke of Valois at the time of his birth.
He was a short lived nephew of Louis XIV.
Charles d'Orléans, Duke of Penthièvre
Prince Charles d' Orléans, Duke of Penthièvre(" Charles Ferdinand Louis Philippe Emmanuel"; 1 January 1820 – 25 July 1828) was the eighth child of the Duke and Duchess of Orléans, future Louis Philippe I and la Reine Marie Amélie.
He was created Duke of Penthièvre, a title previously held by his great grandfather.
Prince Eudes, Duke of Angoulême
Prince Eudes Thibaut Joseph Marie of Orléans, Duke of Angoulême( born 18 March 1968), is the youngest son of Henri, Count of Paris, Duke of France, the late Orleanist claimant to the throne of France, and of Duchess Marie Therese of Württemberg.
Richard Wesley, 1st Baron Mornington
Richard Colley Wesley, 1st Baron Mornington (– 31 January 1758) was an Irish peer, best remembered as the grandfather of Arthur Wellesley, 1st Duke of Wellington.
Louis Jean Marie de Bourbon, Duke of Penthièvre
Louis Jean Marie de Bourbon (16 November 1725 – 4 March 1793) was the son of Louis Alexandre de Bourbon and his wife Marie Victoire de Noailles.
He was also a grandson of Louis XIV of France and his mistress, Madame de Montespan.
From birth he was known as the Duke of Penthièvre.
He also possessed the following titles: Prince of Lamballe (given later as a courtesy title to the duke's only surviving son); Prince of Carignano; Duke of Rambouillet; Duke of Aumale (1775); Duke of Gisors; Duke of Châteauvillain; Duke of Arc-en-Barrois; Duke of Amboise; Count of Eu; Count of Guingamp.
He was the father in law of "Philippe Égalité".
Stephen, Count of Tréguier
Stephen of Penthièvre, Count of Tréguier, 3rd Lord of Richmond( 1058/ 62 – 21 April 1136) was a Breton noble and a younger son of Odo, Count of Penthièvre and Agnes of Cornouaille, sister of Hoël II, Duke of Brittany.
In 1093, he succeeded to the title of Count of Tréguier; in 1098, he succeeded his brother Alain as Lord of Richmond in Yorkshire, England.
Jean II de Brosse
Jean II de Brosse, also Jehan II de Brosse( 1432 – 6 August 1482), was the elder son of Marshal of France Jean I de Brosse.
He would become chamberlain of the king of France in 1449.
He married Nicole, Countess of Penthièvre, daughter of Charles, Seigneur d' Avaugour.
Her father was the third son of John I, Count of Penthièvre, son of Joan, Duchess of Brittany and Charles of Blois.
Nicole later brought him, through inheritance in 1479, the County of Penthièvre in the Duchy of Brittany.
Jehan II de Brosse is known to have rebuilt the donjon in Fouras in 1480 – 1490.

Question: Who is Charles D'Orléans, Duke Of Penthièvre's paternal grandfather?
Answer: Louis Philippe II, Duke of Orléans