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.