To the student of English history the campaign in Flanders, undertaken by Cromwell in 1657 in conjunction with the French king, is one of great interest and importance. Yet, strange to say, to all, except to the plodders in the by-paths of history, it is one of the least known of the episodes in the story of that wonderful man, who according to Macaulay was the ‘greatest prince that ever ruled England.’ Justice has not yet been done to the memory of one to whom the English nation owes more perhaps than to any other ruler, or statesman, to whom for so brief a period the destinies of the country have been entrusted. Something has been attempted of recent years in this direction, and something done—especially by Carlyle—but it amounts to no more than an instalment of the sum total of that justice which was due. When that interest comes to be taken in the measures and achievements of the great Protector which they deserve, it will be found and confessed that the Flanders scheme, which he did not live long enough to fully realise, was one of the greatest of them. It is with that scheme that we have to deal in the present paper.