This is a plan of Guernsey Castle, drawn shortly after 1593. It is a pictorial fortification plan with proposals for improvements. It is possible that Paul Ivey, the leading fortification consultant of the second half of Elizabeth I’s reign, was the draughtsman of this plan as he was studying the defences of the Channel Islands in 1593. The plan is marked with alphabetical references indicating work done previously, the location of suggested earthworks and of a proposed bulwark. At some point the plan has been trimmed resulting in the partial loss of the compass rose.