This paper identifies an English ‘national myth’ of sea-power, based on the folk-memory of the Elizabethan naval war, which powerfully shaped public attitudes and political choices throughout the seventeenth and eighteenth centuries. This myth associated true, patriotic and ever-victorious English sea-power with political liberty, financial profit and, above all, Protestantism. The public judged successive governments on their willingness and ability to realise this programme. Most of them failed on one or both counts, until the elder Pitt made the myth work, and the French revolutionaries changed the rules.