Roger-Bernard IV de Foix (circa 1330 - 1381) was viscount of Castelbon. He was the son of Roger Bernard IV of Foix, viscount of Castelbon and Constance de Luna. He was the eighth degree ancestor of King Henry IV of France.[1]
He was the youngest of the sons of Roger-Bernard IV de Foix, viscount of Castelbon and Constance de Luna, and obtained the viscountcy of Castelbòn (Castelbò in Catalan) and the other Catalan lands.
He married Géraude de Navailles; from this marriage were born: