Spain and Britain had come into conflict during the 1720s over a number of issues, and had recently been at war with each other during the War of the Quadruple Alliance. Disputes over trade were a major cause of aggravation to Anglo-Spanish relations, combined with a fear in Britain that Spain had made an alliance with Austria as the precursor to declaring war on Britain and its ally France. The British decided to try to weaken Spain and discourage them from pursuing the Austrian alliance by denying the Spanish the treasure fleets on which metropolitan Spain had become dependent.