Originally, the Duchy of Chartres (duché de Chartres) was the comté de Chartres, a County. The title of comte de Chartres thus became duc de Chartres. This duchy–peerage was given by Louis XIV of France to his nephew, Philippe II d'Orléans, at his birth in 1674. Philippe II was the younger son and heir of the king's brother, Philippe de France, Duke of Orléans.
Main article: Counts of Blois
The northern portion of the County of Blois, bordering on Normandy, was sometimes alienated as the County of Chartres, but the Counts of Blois who possessed it did not use a separate title for it. In 1391, the death of the only son of Guy II, Count of Blois prompted him to sell the inheritance of the County of Blois to Louis of Valois, Duke of Orléans, merging the title into the royal dukedom.
960-975 Theobald I of Blois († 975), Count of Blois and Chartres, which he took in 960
Theobold I was also known as Theobald the Cheat, or Theobald the Old. He was given the nickname “the Cheat” fighting with his neighbours, among them the kings of France, the dukes of Normandy, and the church of Reims. 
975-995 Odo I, Count of Blois, († 995), Count of Chartres, and Reims (982-995), son of the previous
995-1004 Thibaut II († 1004), Count of Blois, Chartres and Reims, the son of the previous
1004-1023 Eudes II of Blois († 1037), Count of Blois, Chartres, Reims, Meaux and Troyes, brother of the previous
1037-1089 Theobald III, Count of Blois (1019 † 1089), Count of Blois, Chartres, Meaux and Troyes son of Eudes II and Ermengearde d'Auvergne
1089-1102 Stephen II, Count of Blois († 1102), Count of Blois, Chartres and Meaux, son of Thibaut III and Gersende of Maine.
1102-1151 Theobald II, Count of Champagne († 1152), Count of Blois, Chartres and Meaux, and then Count of Champagne in 1125, son of the former.
1151-1191 Theobald V, Count of Blois († 1191), Count of Blois and Chartres, son of the former.
1191-1205 Louis I, Count of Blois († 1205), Count of Blois and Chartres, son of the previous and Alix de France
1205-1218 Theobald VI, Count of Blois († 1218), son of the previous
1218-1248 Isabelle († 1248), Countess of Chartres and Romorantin
1248-1256 Matilda of Amboise († 1256), Countess of Chartres
1256-1280 John I, Count of Blois († 1280), son of the previous
1280-1291 Joan, Countess of Blois († 1292), daughter of the previous
See also: Crown lands of France
After its revival and elevation, the title duc de Chartres was used by the House of Orléans, founded by Philippe de France, duc d'Orléans, and cadet branch of the House of Bourbon.
Renée de France (1509 † 1575), Duchesse de Chartres, daughter of Louis XII and Anne Brittany, married to Hercules d'Este, Duke of Ferrara
Alfonso II d'Este, Duke of Ferrara, their son.
1626-1660 Gaston, Duke of Orléans, (1608–1660) son of King Henri IV
1660-1674 Philippe I, Duke of Orléans, (1640–1701 ) son of King Louis XIII the Just
From 1674 until today, the title of Duke of Chartres is the eldest son of the Duke of Orleans
1674-1701:Philippe II, said "the Pious" (1674–1723) son of preceding;
1703-1723:Louis IV (1703–1752) son of the previous;
1725-1752:Louis Philippe I, Duke of Orléans, "the Fat" (1725–1785) son of preceding;
1752-1785:Louis Philippe II, Duke of Orléans (1747–1793) son of the previous waives his title in 1792 and takes the name of "Philippe Equality";
1785-1793:Louis Philippe III, Duke of Orléans (1773–1850) son of preceding. Access to power in 1830 under the name of Louis-Philippe Ier.
1810-1830:Ferdinand-Philippe (1810–1842) son of preceding
The title is currently held, as a courtesy title, by