Then away "through the wild sea" to Denmark sailed the young pirate king, and here he met a brother viking, one Thorkell the Tall. The two chiefs struck up a sort of partnership; and coasting southward along the western shores of Denmark, they won a sea-fight in the Ringkiobing Fiord, among the "sand hills of Jutland." And so business continued brisk with this curiously matched pirate firm--a giant and a boy--until, under the cliffs of Kinlimma, in Friesland, hasty word came to the boy viking that the English king, Ethelred "The Unready," was calling for the help of all sturdy fighters to win back his heritage and crown from young King Cnut, or Canute the Dane, whose father had seized the throne of England. Quick to respond to an appeal that promised plenty of hard knocks, and the possibility of unlimited booty, Olaf, the ever ready, hoisted his blue and crimson sails and steered his war-ships over sea to help King Ethelred, the never ready. Up the Thames and straight for London town he rowed.
"Hail to the serpent banner! Hail to Olaf the Brave!" said King Ethelred, as the war-horns sounded a welcome; and on the low shores of the Isle of Dogs, just below the old city, the keels of the Norse war-ships grounded swiftly, and the boy viking and his followers leaped ashore. "Thou dost come in right good time with thy trusty dragon-ships, young King," said King Ethelred; "for the Danish robbers are full well entrenched in London town and in my father Edgar's castle."
And then he told Olaf how, "in the great trading place which is called Southwark," the Danes had raised "a great work and dug large ditches, and within had builded a bulwark of stone, timber and turf, where they had stationed a large army."
"And we would fain have taken this bulwark," added the King, "and did in sooth bear down upon it with a great assault; but indeed we could make naught of it."
"Because," said King Ethelred, "upon the bridge betwixt the castle and Southwark have the ravaging Danes raised towers and parapets, breast high, and thence they did cast down stones and weapons upon us so that we could not prevail. And now, Sea-King, what dost thou counsel? How may we avenge ourselves of our enemies and win the town?"