The planned expedition involved several elements: overtaking Spanish treasure ships returning from the Americas loaded with valuables; and assaulting Spanish towns, with the intention of assailing the Spanish economy by weakening the Spanish supply chain and consequently relieving the military pressure on the Electorate of the Palatinate.
Charles I of England, to protect his own dignity and Buckingham, who had failed to ensure the invasion fleet was well supplied, made no effort to inquire as to the cause of the failure of the Cadiz Expedition.