The Danes advanced to this stronghold and took possession of it, and they made it for some time their head-quarters.  It was at once the center from which they carried on their enterprises in all directions about the island, and the refuge to which they could always retreat when defeated and pursued.  In the possession of such a fastness, they, of course, became more formidable than ever.  King Ethelred determined to dislodge them.  He raised, accordingly, as large a force as his kingdom would furnish, and, taking his brother Alfred as his second in command, he advanced toward Reading in a very resolute and determined manner.

He first encountered a large body of the Danes who were out on a marauding excursion.  This party consisted only of a small detachment, the main body of the army of the Danes having been left at Reading to strengthen and complete the fortifications.  They were digging a trench from river to river, so as completely to insulate the castle, and make it entirely inaccessible on either side except by boats or a bridge.  With the earth thrown out of the trench they were making an embankment on the inner side, so that an enemy, after crossing the ditch, would have a steep ascent to climb, defended too, as of course it would be in such an emergency, by long lines of desperate men upon the top, hurling at the assailants showers of javelins and arrows.

While, therefore, a considerable portion of the Danes were at work within and around their castle, to make it as nearly as possible impregnable as a place of defense, the detachment above referred to had gone forth for plunder, under the command of some of the bolder and more adventurous spirits in the horde.  This party Ethelred overtook.  A furious battle was fought.  The Danes were defeated, and driven off the ground.  They fled toward Reading.  Ethelred and Alfred pursued them.  The various parties of Danes that were outside of the fortifications, employed in completing the outworks, or encamped in the neighborhood, were surprised and slaughtered; or, at least, vast numbers of them were killed, and the rest retreated within the works—­all maddened at their defeat, and burning with desire for revenge.

The Saxons were not strong enough to dispossess them of their fastness.  On the contrary, in a few days, the Danes, having matured their plans, made a desperate sally against the Saxons, and, after a very determined and obstinate conflict, they gained the victory, and drove the Saxons off the ground.  Some of the leading Saxon chieftains were killed, and the whole country was thrown into great alarm at the danger which was impending, that the Danes would soon gain the complete and undisputed possession of the whole land.

The Saxons, however, were not yet prepared to give up the struggle.  They rallied their forces, gathered new recruits, reorganized their ranks, and made preparations for another struggle.  The Danes, too, feeling fresh strength and energy in consequence of their successes, formed themselves in battle array, and, leaving their strong-hold, they marched out into the open country in pursuit of their foe.  The two armies gradually approached each other and prepared for battle.  Every thing portended a terrible conflict, which was to be, in fact, the great final struggle.