Béatrix de Pierrepont

Béatrix de Pierrepont (1310–1349), called de Roucy-Pierrepont, was the daughter of John V, Count of Roucy and Braine, and Marguerite de Beaumez, and inherited several seigneuries. On 8 July 1329 she married Louis II, Count of Sancerre, and bore him seven children, including John III, who succeeded him, and Louis, later marshal and constable of France.

Her husband and father were both killed at Crécy on 26 August 1346. As widowed countess she confirmed a customary right of the lord of Pesselières as marshal of the county in 1348, and died the next year.