During the winter months the Danish fleet had apparently been moored at the old viking rendezvous, the Isle of Wight, or in some neighbouring harbour. In April, Canute was back from his march to York and was getting his ships in readiness for further operations, when the death of Ethelred checked his movements. With remarkable promptness the notables (perhaps those of Southern England only) came together at some point unknown, awarded the kingship to Canute, and proscribed all the descendants of Ethelred. This done, they adjourned to Southampton to give their pledges of loyalty. It was a body of great respectability that thus gathered to pay homage, containing, as it did, both laymen and churchmen, lords, bishops, and abbots. The election must have been held some time about the close of the month, for by the seventh of May, Canute was at Greenwich with his fleet.[116]
In London, too, an assembly had met and a king had been chosen. Edmund was in the city when his father died. The chiefs present, "all the witan who were in London and the citizens of London," as the Chronicler carefully puts it, at once proclaimed Edmund king. Thus both the peace party and the war party had acted. It is clear, however, that neither of these elections could lay any claim to legality; neither assembly could pretend to represent the entire kingdom; between the death of Ethelred in April and the accession of Canute at the following Christmas, England had no lawful ruler.
Canute at once proceeded to the siege of London. His plan was to isolate the city completely, to block the Thames both above and below the town, and to prevent all intercourse with the country to the north. To accomplish this investment, a canal was dug around London Bridge wide enough to permit the long but narrow viking ships to pass into the stream west of the city. On the north side a ditch was dug enclosing the entire town, "so that no man could come either in or out."[117] Vigorous efforts were made from time to time to storm the fortifications, "every morning the lady on the Thames bank sees the sword dyed in blood"[118]; but the townsmen held their own. The siege continued through the month of May and perhaps till late in June, when it seems to have been interrupted by disquieting news from the West.
On the approach of the fleet, or at least before the investment had become complete, Edmund left London. We are told that his departure was secret, which is probable, as it was surely to his interest to keep Canute in the dark as to his whereabouts. We do not know who directed the defence of London during his absence; a year or two later, Thietmar, the bishop of Merseburg, introduced into his Chronicle a confused account of these events, in which Queen Emma is made to play an important part in the resistance of 1016.[119] It may be that the Queen had returned with Ethelred, but it is doubtful. When Canute heard that his enemies were mustering in the Southwest, he seems to have detached a part of his force and sent it westward to look for Edmund. At Penselwood, near Gillingham in Dorset, the Danes came upon the Saxon forces. Edmund's success in raising the West had not been great; but, "trusting in the help of God," he gave battle and won a victory.[120] It is likely that the affair at Penselwood was little more than a skirmish, for it seems to have made small difference in the relative positions of the contending forces. But it gave Edmund what he sorely needed—the prestige of success. A month later, battle was again joined at Sherstone, a little farther to the north near Malmesbury in the upper part of Wiltshire.
The encounter at Sherstone was a genuine battle fiercely fought, one that lived long in the memories of Englishmen. It occurred after the feast of Saint John, probably in the early days of July. The earlier sources do not mention Canute in connection with this fight; with Eric he was apparently continuing the siege of London. The western campaign was evidently in Thurkil's hands; the sources also mention three prominent Englishmen, Eadric, Almar Darling, and Algar, as fighting on the Danish side.[121] The Encomiast, who speaks of a Danish victory at Sherstone, gives the entire credit to Thurkil, whom he naively describes as a fervent believer "continuously sending up silent prayers to God for victory."[122]
Sherstone was at best a drawn battle, neither side claiming a victory. The Anglo-Norman historians, true to their habit of looking for some traitor on whom to blame the outcome, could not overlook Eadric; he is said to have picked up the head of a soldier who bore some resemblance to Edmund and thus to have deceived the Saxons into believing that their leader was dead.[123] The tale is obviously mythical; if Henry of Huntingdon is to be trusted, the trick was played again later in the year at Ashington.
After the encounter at Sherstone, Thurkil seems to have joined Canute before London; but his whole force did not return with him. Eadric once more had shifted his allegiance; he had made peace with Edmund and had joined him against the invader. Whatever his motives may have been, there can be no dispute as to the importance of his new move. Edmund's army was strengthened, as was doubtless his prestige in the Midlands. For the third time he had an army at his command, gathered, it seems, from the region north of the Thames. With this host he marched to the relief of London. On the appearance of this force, Canute found himself in a difficult situation: to maintain a siege and fight a vigorous foeman at the same time, required forces greater than those at the Dane's command. Prudence was Canute's greatest virtue, and he promptly raised the siege and withdrew to his ships. Edmund seems to have come up with his forces to Brentford, just as the Danes were busy crossing to the south bank. The enemy fled; but many of the English were drowned "because of their own heedlessness, as they rushed ahead of the main force to get at the booty."[124] Evidently the whole Danish force had not left London, as the fight at Brentford was two days after the city had been relieved.
With the relief of London, the English seem to have considered their duty done, and soon Edmund found himself once more without an army.[125] It may, of course, be that the apparent lack of patriotism was due to the necessities of the harvest season, which must have arrived by this time. The tireless Edmund next made a visit to Wessex to raise the militia there. While he was seeking recruits, the Danes returned to London, resumed the siege, and attacked the city furiously by land and sea, but as usual failed to take it.