A ditch was dug around the edge of the bailey and the earth taken out was piled up inside to form the bank. Where possible, the ditch was allowed to fill with water from a nearby river or stream to provide extra defence.

On top of the bank a palisade of wooden planks or logs was constructed to add extra height. A wall walk was usually built behind the palisage to allow the defenders to see over the top and fire missiles down on attackers below who were attempting the climb the bank.

The palisade continued all the way around the edge of the bailey and its only real threat was from fire. This threat eventually lead to the introduction of stone for building material.