The principal, and to us the alone interesting, of his exploits seem to have lain in England, and, what is further notable, always on the anti-Svein side. English books do not mention him at all that I can find; but it is fairly credible that, as the Norse records report, in the end of Ethelred's reign, he was the ally or hired general of Ethelred, and did a great deal of sea-fighting, watching, sailing, and sieging for this miserable king and Edmund Ironside, his son. Snorro says expressly, London, the impregnable city, had to be besieged again for Ethelred's behoof (in the interval between Svein's death and young Knut's getting back from Denmark), and that our Olaf Haraldson was the great engineer and victorious captor of London on that singular occasion,--London captured for the first time. The Bridge, as usual, Snorro says, offered almost insuperable obstacles. But the engineering genius of Olaf contrived huge "platforms of wainscoting [old walls of wooden houses, in fact], bound together by withes;" these, carried steadily aloft above the ships, will (thinks Olaf) considerably secure them and us from the destructive missiles, big boulder stones, and other, mischief profusely showered down on us, till we get under the Bridge with axes and cables, and do some good upon it. Olaf's plan was tried; most of the other ships, in spite of their wainscoting and withes, recoiled on reaching the Bridge, so destructive were the boulder and other missile showers. But Olaf's ships and self got actually under the Bridge; fixed all manner of cables there; and then, with the river current in their favor, and the frightened ships rallying to help in this safer part of the enterprise, tore out the important piles and props, and fairly broke the poor Bridge, wholly or partly, down into the river, and its Danish defenders into immediate surrender. That is Snorro's account. On a previous occasion, Olaf had been deep in a hopeful combination with Ethelred's two younger sons, Alfred and Edward, afterwards King Edward the Confessor: That they two should sally out from Normandy in strong force, unite with Olaf in ditto, and, landing on the Thames, do something effectual for themselves. But impediments, bad weather or the like, disheartened the poor Princes, and it came to nothing. Olaf was much in Normandy, what they then called Walland; a man held in honor by those Norman Dukes. What amount of "property" he had amassed I do not know, but could prove, were it necessary, that he had acquired some tactical or even strategic faculty and real talent for war. At Lymfjord, in Jutland, but some years after this (A.D. 1027), he had a sea-battle with the great Knut himself,--ships combined with flood-gates, with roaring, artificial deluges; right well managed by King Olaf; which were within a hair's-breadth of destroying Knut, now become a King and Great; and did in effect send him instantly running. But of this more particularly by and by.