This episode covers how Spain and Portugal emerged as leading Atlantic powers in the late 15th and 16th centuries, but their global empires quickly provoked widespread piracy and corsair activity, especially from North Africa and France, as other nations rejected the Treaty of Tordesillas and targeted Spanish treasure routes. In the Mediterranean, Barbary corsairs—most famously the Barbarossa brothers, backed by the Ottoman Empire—fought Spain in a prolonged struggle marked by raids, slavery, and ransom, while neither side achieved decisive control. In the Caribbean, French corsairs pioneered large-scale piracy against Spain’s poorly defended colonies, forcing Spain to adopt costly defensive systems that shaped the long-term pattern of piracy, contraband trade, and imperial conflict in the Americas.