Guillemette of Neufchâtel

Guillemette de Neufchâtel was a vassal in the Holy Roman Empire. She was Countess of Montbéliard between 1282 and 1317.
She was 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:

Othenin "the Mad", who succeeded her as Count of Montbéliard
Agnes of Montbéliard, married Henry I, Count of Montbéliard, who inherited Montbéliard after Othenin's death
Joanna, married:
# Ulrich III, Count of Pfirt
# Rudolf Hesso, Margrave of Baden-Baden
# William, Count of Katzenelnbogen
Margaret, married William of Antigny, Prince of Sainte-Croix
Adelaide, married John II, Count of Chalon-Auxerre

In 1283, her great-grandfather, Theodoric III, Count of Montbéliard 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.