During this period Oliver Cromwell also faced challenges in foreign policy. The First Anglo-Dutch War which had broken out in 1652, against the Dutch Republic, was eventually won by Admiral Robert Blake in 1654. Having negotiated peace with the Dutch, Cromwell then proceeded to engage the Spanish in warfare, through his Western Design. This involved secret preparations for an attack on the Spanish colonies in the Caribbean. This resulted in the invasion of Jamaica, which then became an English colony. The Lord Protector became aware of the contribution the Jewish community made to the economic success of Holland, now England's leading commercial rival. It was this—allied to Cromwell's toleration of private worship of non-puritans—that led to his encouraging Jews to return to England, 350 years after their banishment by Edward I, in the hope that they would help speed up the recovery of the country after the disruption of the Civil Wars.