Naval victories at Mylae in 260BC and Sulci in 258BC, and their frustration at the continuing stalemate in Sicily, led the Romans to focus on a sea-based strategy and to develop a plan to invade the Carthaginian heartland in North Africa and threaten its capital, Carthage. Both sides were determined to establish naval supremacy and invested large amounts of money and manpower in increasing and maintaining the size of their navies.