I would be interested to know if anyone can point to useful sources about English flags used during the First Anglo-Dutch War. So far, Willem van de Velde de Oude drawings seem to be a useful source, although it is hard to know how accurate his Dungeness drawing is. I have also looked at several Reinier Nooms paintings. I have been somewhat surprised at the ubiquity of white vanes and flags with the red St. George's cross. That is even true in Willem van de Velde de Oude drawings for Livorno, Dungeness, and even Scheveningen (Terheide).