CHATILLON, the name of a French family whose history has furnished material for a large volume in folio by A. du Chesne, a learned Frenchman, published in 1621. But in spite of its merits this book presents a certain number of inaccurate statements, some of which it is important to notice. If, for instance, it be true that the Châtillons came from Châtillon-sur-Marne (Marne, arrondissement of Reims), it is now certain that, since the 11th century, this castle belonged to the count of Champagne, and that the head of the house of Châtillon was merely tenant in that place. One of them, however, Gaucher of Châtillon, lord of Crécy and afterwards constable of France, became in 1290 lord of Châtillon-sur-Marne by exchange, but since 1303 a new agreement allotted to him the countship of Porcien, while Châtillon reverted to the domain of the counts of Champagne. It may be well to mention also that, in consequence of a resemblance of their armorial bearings, du Chesne considered wrongly that the lords of Bazoches and those of Château-Porcien of the 12th and 13th centuries drew their descent from the house of Châtillon.
The most important branches of the house of Châtillon were those of (1) St Pol, beginning with Gaucher III. of Châtillon, who became count of St Pol in right of his wife Isabella in 1205, the last male of the line being Guy V. (d. 1360); (2) Blois, founded by the marriage of Hugh of Châtillon-St Pol (d. 1248) with Mary, daughter of Margaret of Blois (d. 1230), - this branch became extinct with the death of Guy II. in 1397; (3) Porcien, from 1303 to 1400, when Count John sold the countship to Louis, duke of Orleans; (4) Penthièvre, by the marriage of Charles of Blois (d. 1364) with Jeanne (d. 1384), heiress of Guy, count of Penthièvre (d. 1331), the male line becoming extinct in 1457.
See A. du Chesne, Histoire généalogique de la maison de Chastillon-sur-Marne (1621); Anselme, Histoire généalogique de la maison royale de France, vi. 91-124 (1730).
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)