CHAPTER IV: THE INVASION OF WESSEX.
Edmund and Egbert devoted most of their time to the building of the new fort, living very simply, and expended the whole of the revenues of the lands on the payment of the freemen and masons engaged upon the work.
The Roman fort was a parallelogram, the sides being about 200 yards long, and the ends half that length.

It was surrounded by two earthen banks with wide ditches.

These were deepened considerably, and the slopes were cut down more sharply.

The inner bank was widened until it was 15 feet across the top.
On this the wall was built.

It was faced on both sides with square stones, the space between filled up with rubble and cement, the total thickness being 4 feet.