Willem IV of Horne
Willem IV of Horne (c. 1302–1343), son of Gerard I, was lord of Horne, Altena, Weert and Heeze. He took charge of Altena in 1321, but the count of Kleve refused to invest him, favouring his half-brother Dirk; Count William III of Holland guaranteed his position in 1327.
He married Oda of Putten by 1316 and Elisabeth of Kleve-Hülchrath in 1336, with eleven children. He granted Heeze to Gerard II in 1342 and died in 1343.