The Ottoman Empire and England were allies of convenience against Spain under Philip II Habsburg, for whom Sigismund held sympathy. While Elizabeth's armies were fighting Catholic forces in the Low Countries to prevent the Spanish from gaining secure harbours on the Channel, England also served Turkish interests by diverting Spain from dominating the Mediterranean. Poland, on the other hand, was engaged in continuous skirmishes with the Turks on its southeastern flank. The good will of Poland was crucial as the country was the source of grain and timber necessary to maintain the English navy. Edward Barton, Elizabeth's ambassador to the Ottoman Empire, has warned that if the Turks were to launch a campaign against Poland, England would respond.