In the wake of the execution of Charles I, the Adventurers gained control over the Council of State’s external trade policy, culminating in the adoption of the Navigation Act of 1651. In swift succession, they arranged finance and logistics for Cromwell’s conquest of Ireland and parliament’s reducing of the Atlantic colonies. The Caribbean plantations were converted to sugar production and the Adventurers took a leading role in adapting these plantations to the African slave trade. This chapter demonstrates that a core group of merchants dominated the greater part of England’s foreign trade, state finance and state expenditure. They had developed an integrated fiscal state and were thus able to project considerable political influence as well as profiting enormously from these activities.