Guillemette of Neufchâtel
Guillemette de Neufchâtel (1260–1317) was a French noblewoman, the daughter of Amadeus, Count of Neufchâtel and his wife, Jordanna of Arberg. In 1259, her great-aunt Margaret, married Richard of Neufchâtel-en-Bourgogne. As her dowry, she brought the Lordships of Blamont, Châtelot, Belmont, and Cuisance into the marriage. The Lords of Neufchâtel-en-Bourgogne placed Blamont under the protection of the Duke of Burgundy and thus detached it from Montbéliard. In 1282, Guillemette married Reginald of Burgundy. They had five children: In 1283, her great-grandfather, Theodoric III, Count of Montbéliard (1205–1283) died. He had outlived  all his children and in his will, he left the County of Montbéliard to his great-granddaughter Guillemette. Theobald III of Neufchâtel, who was a grandchild of Theodoric III and who wanted Montbéliard for himself, conspired with Reginald's brother Otto IV to have Montbéliard recognized as a fief of Burgundy. To resolve this, Reginald ceded Blamont and Châtelot to Theobald.