Châtillon-sur-Marne was a Roman camp, Castellionum super Matronam, long before the tenth century, when it was a major town in the county of Blois. It is near the center of the Champagne region. The seigneurs of the town intermarried several times with their feudal lords, the counts of Blois, before Blois itself came into their family in the thirteenth century.

The earliest seigneur de Châtillon on record is Raoul de Cambrai (died c982), son of one Baudouin Balza, whsoe antecedents are not known. Raoul's son Hervé was Vicomte de Rheims around the turn of the century, and died in 999 or 1000. His wife was Gisèle of Cambrai (also of unknown background). Their son Milo, seigneur de Châtillon (died c1044) married Avemelle de Montfort (died 1031). At least two sons: (1) Gui, see below, and (2) Eudes, who became the great Pope Urban II (1088-1099), instigator of the Crusades.

Gui I, seigneur de Châtillon (died p1076) married Ermengarde de Choisy. Their son Gaucher I (died 1097) brought the family into greater prominence by marrying Mahaut de Louvaine (died c1112), a daughter of Reginar, younger brother of Count Henri II of Louvaine.

Gaucher I and Mahaut had at least one son, Henri I (living in 1135), who married Ermengarde de Montjoie. They were the parents of two children that we know of: (1) Renaud, see below; and (2) Gaucher II, see farther below.

Renaud I (1126-1187), seigneur de Châtillon, joined the Second Crusade in 1147 and entered the service of Princess Constance de Hauteville of Antioch (1127-1163), who had been widowed in 1149. (Her first husband was Raymond of Poitiers; see Poitiers for their descendants.) Renaud became Prince of Antioch by marrying her secretly in 1153; the marriage had not been approved by her overlord the king of Jerusalem. They had two daughters: (1) Agnes (1154-1184), who married Béla III, King of Hungary and Croatia (see Árpád), and Marie, who was the second wife of Emperor Manuel I Comnenus and mother of his heir Alexios II. Note that some sources consider Renaud entirely unrelated to this family, being seigneur de Châtillon-sur-Loing rather than -sur-Marne, but I follow Stirnet here.

Renaud's brother and presumptive heir (in France) was Gaucher II (died 1167), who married Ada de Roucy. Note that there is no question of Gaucher being the son of Henri I; the doubt has to do with Renaud. As Gaucher died before Renaud, the next heir to the seigneury de Châtillon was their son Gui II (c1147-1180), who also died before his uncle Renaud. Gui married Adèle, daughter of Robert I 'le Grande,' Comte de Dreux, by Hedwige d'Evreux of the Salisbury family. (She was married four times; he was her second husband). They had two children: Gaucher III (see below), and Alix, Dame de Clichy la Garenne, who married Guillaume V de Garlande (two daughters; one of them, Marie, married the Crusader Geoffroi V de Joinville).

Gaucher III (c1166-1219), seigneur de Châtillon, married Elisabeth, daughter and heiress of Hugues IV, comte de St-Pol, by Yolande of Hainault. They were the parents of three children: (1) Hugues V de Châtillon, see below; (2) Gui III de Châtillon, see farther below; and (3) Eustachie (c1215-1273), who married Robert II de Wavrin (possibly Martin ancestors, still working on it), and also Daniel de Béthune (no children, but we are descended from two of his brothers).

Hugues V de Châtillon (c1196-1248), comte de St-Pol, is also called comte de Blois by reason of his marriage to Marie, Dame d'Avesnes, daughter of Wautier II d'Avesnes and Marguérite, daughter and heiress of Thibaut V of Blois (see Avesnes and Blois). They had two children: (1) Gui de Châtillon, 2nd comte de St-Pol, see below; and (2) Gaucher IV, seigneur de Châtillon (he married Isabelle de Villehardouin; one son, Gaucher, seigneur de Porcien - many descendants, including some in Québec; still working on this; but also including Jacquetta of Luxembourg, see below under Porcien).

Gui de Châtillon, 2nd comte de St-Pol (c1225-1289) married as her second husband Matilda (1224-1288), daughter of Henri II of Brabant by Marie of Swabia (a granddaughter of Frederick Barbarossa). Matilda is also our ancestor by her first husband, Count Robert I of Artois. They had two sons: (1) Gui de Châtillon, 3rd comte de St-Pol, see below; and (2) Hugues II de Châtillon, Count of Blois and St. Pol (1258-1303), many royal descendants, but I think not us.

Gui de Châtillon, 3rd comte de St-Pol (c1254-1317) married Marie, Dame d'Elincourt (1268-1139), daughter of Jean II de Dreux, Duke of Brittany by Princess Beatrice of England (see Dreux and Plantagenet). They were the parents of four children: (1) Jean de Châtillon, comte de St-Pol, see below; (2) Beatrix, married Jean de Flanders; (3) Isabeau (died 1360), married Guillaume de Guisnes, seigneur de Coucy; and (4) Mahaut, married as his third wife Charles de Valois, who is our ancestor by his first wife.

Jean de Châtillon, comte de St-Pol (died 1334) married Jeanne de Fiennes, daughter of Jean de Fiennes of Tingry by Isabelle of Flanders (and a descendant of Eustachie de Châtillon and Daniel de Bethune, see above). One child: Mahaut de Châtillon (c1334-1378), married Guy, Count of Luxembourg, St-Pol, Roussy and Fiennes (c1340-1371). The senior Châtillon line ends with her, and the titles pass to the Luxembourg family. Mahaut's great-granddaughter is Jacquetta of Luxembourg.

We return to Gui III de Châtillon (c1196-1236), second son of Hugues IV: he married Agnes de Donzy and had one daughter, Yolande de Châtillon, comtesse de Nevers, d'Auxerre et de Tonnerre (died 1254); she married Archambaut (Archembaud) VIII/IX de Dampierre, seigneur de Bourbon - see that page for descendants. Their great-granddaughter Yolande of Flanders married Wautier II d'Enghien and they were great-great-great-grandparents of Jacquetta of Luxembourg.

The seigneurs de Porcien

Gaucher (c1260-1329), son of Gaucher IV, seigneur de Châtillon and Isabelle de Villehardouin above, was seigneur de Porcien or Porcéan, a town in the Ardennes region of Champagne. He married twice: first Isabelle, daughter of Robert de Dreux and Clémence, Vicomtesse de Châteaudun; and second Hélisende de Vergy, daughter of Jean I de Vergy and Marguérite de Noyers. All children are believed to be from the first marriage: (1) Gaucher II de Porcien (died 1325), had descendants; (2) Jeanne, married Gautier V de Brienne et di Lecce, Duke of Athens, etc; (3) Mathilde, married Charles II d'Alençon; (4) Marie, married Guichard VI de Beaujeu; (5) Gui (died 1362), whose son Gaucher X eventually inherited the seigneury of Châtillon-sur-Marne; (6) Jean, seigneur de Châtillon de Gandelus, many descendants, mostly in Germany; and (7) Hugues, seigneur de Rozoy-en-Thierache - many descendants, including the Orléans branch of the French royal family.

The arms shown above were those used by Gaucher IV in the thirteenth century. Without the black lion on the gold background, these are the original Châtillon arms.