Marquesses of Valdeosera Marqueses de Valdeosera Records #4 Holders Family filter On/Off 6 Manuela Luisa de Castilla y Quevedo * 1800 7 Juan António O'Neill y Castilla, marquess of la Granja * 1821 8 Tulio O' Neill y Salamanca, 10th count of Benagiar * 1866 María del Carmen O' Neill y Castrillo, marquise of Valdeosera * 1920 Corrections and Updates To suggest a correction or an update. Click Here