August 2 (?), 924: Death of Ælfweard, son of King Edward the Elder
The Anglo-Saxon Chronicle records that King Edward's son Ælfweard died at Oxford 16 days after his father (July 17), and that he was buried at Winchester. Two Winchester sources add that Ælfweard was king after Edward's death: a history composed in the 980s notes that he was "crowned with royal tokens", and a regnal list (a list of the kings and the length of their reigns) gives him a reign of four weeks. (This would put Ælfweard's death in mid-August, hence the question mark over "August 2".)
It is odd that the Chronicle does not mention Ælfweard's kingship, and it may be that some awkward facts are being smoothed over. Edward the Elder left sons by three women on his death in 924. By Ecgwynn he had Æthelstan (king 924-39), who would have been about thirty in 924. By Ælfflæd he had Ælfweard (d. 924) and Eadwine (d. 933), who were perhaps in their mid-twenties. By Eadgifu he had Edmund (king 939-46) and Eadred (king 946-55), who were probably under five in 924 and so not relevant to the succession.
It is very surprising that although Æthelstan became king in 924 his official coronation was not until 4 September 925. It is further noteworthy that Ælfweard's brother (Æthelstan's half-brother) Eadwine died in 933. The Chronicle notes simply that he was drowned at sea. A later tenth-century account (the Acts of the Abbots of St Bertin's; Eadwine was buried at St Bertin's on the Continent) records that in 933 "King" Edwin, driven by some disturbance in his kingdom, took ship and was wrecked in a storm.
One could certainly read these events as suggesting a dispute over the kingship in 924 between the son of Ecgwynn and the sons of Ælfflæd, and take the fact that only Winchester sources record Ælfweard's kingship to reflect that Winchester stood for Ælfweard and Eadwine and against Æthelstan. And that pro-Æthelstan or at least more cautious heads ruled the centres where the manuscripts of the Chronicle were written.
William of Malmesbury, writing in the twelfth century, waxes lyrical about a Winchester plot to capture Æthelstan and blind him, and the evil counsellor who made Æthelstan believe that Eadwine was plotting against him; but since there's no other evidence to back up these stories and parts of the story are pure folktale, it's hard to tell whether to rely on him. This is a regular problem with William (see also the death of Godwine): many of the really intriguing tales about Anglo-Saxon England come from him alone, but since he lived some time after the events and he's more of a story-teller than an "academic" historian, it is never clear how much of them he makes up out of whole cloth.