England is small and contains relatively few natural resources. During Great Britain's mercantilist period, the prevailing economic wisdom suggested that the empire's many colonies could supply raw materials and resources to the mother country and subsequently be used as export markets for the finished products. The resulting favorable balance of trade was thought to increase national wealth. Great Britain was not alone in this line of thinking. The French, Spanish and Portuguese competed with the British for colonies; it was thought, no great nation could exist and be self-sufficient without colonial resources.