King Abdullah leaves Riyadh hospital after back surgery . President Obama says the United States has lost a ' valued ally ' who had been ill for some time and is in a New York hospital . Prince Nayef , a reputed conservative , is a likely successor .
King Abdullah leaves Riyadh hospital after back surgery . President Obama says the United States has lost a 'valued friend ' Sultan had been ill for some time and died in a New York hospital . Prince Nayef , a reputed conservative , is a likely successor .