Four manuscript charts of British ports, and notes on them, were made in the 1590s by an English Catholic pilot, N. Lambert. They were sent to Don Juan de Idiáquez, Philip II's secretary, through the mediation of an English Jesuit exile, Robert Persons (or Parsons). Lambert also offered to pilot Spanish ships and guide Spanish troops in raids on the coasts of England and Wales, and prepared a list of appropriate targets. Being some of the earliest charts of the ports concerned, and hitherto unpublished, they are here presented with relevant background material.