They built a bridge across the water where the herdsman's boat had been accustomed to ply.

They raised two towers to watch and guard the bridge.

All these defenses were indeed of a very rude and simple construction; still, they answered the purpose intended.

They afforded a real protection; and, more than all, they produced a certain moral effect upon the minds of those whom they shielded, by enabling them to consider themselves as no longer lurking fugitives, dependent for safety on simple concealment, but as a garrison, weak, it is true, but still gathering strength, and advancing gradually toward a condition which would enable them to make positive aggressions upon the enemy.
The circumstance which occurred to hasten the development of Alfred's plans, and which was briefly alluded to at the close of the last chapter, was the following: It seems that quite a large party of Danes, under the command of a leader named Hubba, had been making a tour of conquest and plunder in Wales, which country was on the other side of the Bristol Channel, directly north of Ethelney, where Alfred was beginning to concentrate a force.

He would be immediately exposed to an attack from this quarter as soon as it should be known that he was at Ethelney, as the distance across the Channel was not great, and the Danes were provided with shipping.
Ethelney was in the county called Somersetshire.