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.
Carolingian Counts
882-886 Hastein, Viking chieftain, beat Carloman II of France in 879, agreed to settle and received the County of Chartres. He sold it in 886 to finance an expedition during which he disappeared.
Hereditary Counts
House 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
Married to Luitgarde of Vermandois
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 Married to Bertha of Burgundy
995-1004 Theobald II of Blois († 1004), Count of Blois, Chartres and Reims, the son of the previous
1004-1037 Odo II of Blois († 1037), Count of Blois, Chartres, Reims, Meaux and Troyes, brother of the previous Married first in 1003 to Mathilde de Normandie († 1006) Married second to Ermengearde of Auvergne
1037-1089 Theobald III, Count of Blois (1019 † 1089), Count of Blois, Chartres, Meaux and Troyes son of Eudes II and Ermengearde d'Auvergne Married first to Gersende of Maine Married second to Adele of Valois
1089-1102 Stephen II, Count of Blois († 1102), Count of Blois, Chartres and Meaux, son of Thibaut III and Gersende of Maine. Married to Adela of Normandy
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. Married in 1123 to Matilda of Carinthia († 1161)
1151-1191 Theobald V, Count of Blois († 1191), Count of Blois and Chartres, son of the former. Married first to Sibylle of Châteaurenard Married second in 1164 to Alix of France
1191-1205 Louis I, Count of Blois († 1205), Count of Blois and Chartres, son of the previous and Alix de France Married in 1184 to Catherine of Clermont
1205-1218 Theobald VI, Count of Blois († 1218), son of the previous
Married first to Mahaut of Alençon
Married second to Clemence des Roches
1218-1248 Isabelle († 1248), Countess of Chartres and castellan of Romorantin
Married first to Sulpice III d'Amboise
Married second to Jean II de Montmirail († 1244).
House of Amboise
1248-1256 Matilda of Amboise († 1256), Countess of Chartres
Married to Richard II, Count of Beaumont, then to Jean II de Nesle
House of Blois-Châtillon
Theobald V, Count of Blois married his second wife in 1164 to Alix of France and father of: Margaret, Countess of Blois, married to Walter II of Avesnes, mother of: Mary, Countess of Blois († 1241), married to Hugues de Châtillon (v.1196 † 1248), Count of Saint-Pol, mother of:
1256-1280 John I, Count of Blois († 1280), son of the previous
Married 1254 to Alice of Brittany (1243-1288)
1280-1286 Joan, Countess of Blois († 1292), daughter of the previous
Married 1272 to Peter of France († 1284), Count of Alençon and Valois. In 1286, she sold the county of Chartres to Philip IV of France
Counts apanage
House of Valois
1290-1302 and 1310-1325 Charles, Count of Valois, (1270 † 1325), Count of Valois, Alençon, Perche, Chartres, Anjou and Maine Married first to Margaret, Countess of Anjou and Maine (1273 † 1299) Married second to Catherine I, Latin Empress (1274 † 1308) Married third to Mahaut of Châtillon (1293 † 1358), cousin of Jeanne de Blois-Châtillon
1302-1310 John of Valois (1302-1310), Count of Chartres, son of Charles of Valois and Catherine I
1325-1328 (1318-1328), Count of Chartres, son of Charles of Valois and Mahaut of Châtillon
1328-1346 Charles II of Alençon (1297 † 1346), Count of Alençon, Chartres, son of Charles of Valois and Margaret of Anjou