... William adds that his father nominated him in his will as his successor—a thing which was not in the power of an Old English king—though he might have presented him to the Witan as a colleague during his lifetime.  But all this story is rendered more than doubtful by the plain fact that in many charters of Edward, from the year 908 onward, Aethelstan signs as filius regis directly after the bishops, and before his next brother Aelfweard, the elder son of Aelflaed, the king's second spouse... (England Before the Norman Conquest, Oman, 1910)