All through the latter half of 1654 mysterious preparations went forward with great activity in the English dockyards, and France, Spain, and Holland each trembled lest they might be turned against herself. But the existing organisation in England was unequal to the effort. To equip two fleets of forty and of twenty-five ships for a long and distant cruise was a heavy task in itself; but to add to this the transport of six thousand men over three thousand miles of ocean for an expedition to the tropics was to tax the resources of the naval and military departments to excess. The burden of the duty fell upon John Desborough, major-general and commissioner of the Admiralty, who was not equal to thinking out the details of such an enterprise nor disposed to give himself much trouble about them. His difficulties were increased by the rascality of contractors, and by the composition of the expeditionary force. By a gigantic error, which has not yet been unlearned, Cromwell, instead of sending complete regiments under their own officers, made up new corps, partly of drafts selected by various colonels and probably containing the men of whom they were most anxious to be rid, and partly of recruits drawn from the most restless and worthless of the nation. He returned in fact to the old system that had so often been found wanting in the days of Elizabeth, of James, and of Charles.
The distribution of command was also faulty. The military commander-in-chief was Robert Venables, who had made a reputation as a hunter of Tories in Ireland; the Admiral joined with him was William Penn, who is unjustly remembered rather as the father of a not wholly admirable Quaker than as one of the ablest and bravest naval officers of his day. But as if two commanders were not already sufficient, there were joined with them three civil commissioners, one Gregory Butler, an officer who had served in the Civil War, Edward Winslow, a civilian and an official, and the Governor of Barbados, Daniel Searle. There was of course nothing new in the presence of civil commissioners on the staff, and a general's instructions since the days of Henry the Eighth had usually bound him to act by the advice of his Council of War only; but it is abundantly evident that Winslow was employed not only as a commissioner, but as a spy on his colleagues, or on some one of them whose loyalty was suspected. It is strange that so sensible a man as Cromwell should have made such a mistake as this. Monk was the man whom he had wished to send, could he have spared him from Scotland; but failing Monk, Penn and Venables were both of them men who had shown ability in their previous service.