William III, Princely Count of Henneberg-Schleusingen Princely count of Henneberg (1434–1480) Parents William II, Princely count of Henneberg-Schleusingen Catherine of Hanau Children Margarethe, Gräfin von Henneberg-Schleusingen William IV, Count of Henneberg-Schleusingen Siblings Philip II of Rieneck Philip I of Rieneck Johann II. von Henneberg-Schleusingen Gräfin Margarethe von Henneberg-Schleusingen Partners Margarethe von Braunschweig-Wolfenbüttel