Like the army, the origins and traditions of the Ptolemaic navy were rooted in the wars following the death of Alexander in 320 BC. Various "diadochi" competed for naval supremacy over the Aegean and eastern Mediterranean, and Ptolemy I founded the navy to help defend Egypt and consolidate his control against invading rivals. He and his immediate successors turned to developing the navy to project power overseas, rather than build a land empire in Greece or Asia. Notwithstanding an early crushing defeat at the Battle of Salamis in 306 BC, the Ptolemaic navy became the dominant maritime force in the Aegean and eastern Mediterranean for the next several decades. Ptolemy II maintained his father's policy of making Egypt the preeminent naval power in the region; during his reign (283 to 246 BC), the Ptolemaic navy became the largest in the Hellenistic world and had some of the largest warships ever built in antiquity. The navy reached its height following the victory of Ptolemy II during the First Syrian War (274–271 BC), succeeding in repelling both Seleucid and Macedonian control of the eastern Mediterranean and the Aegean. During the subsequent Chremonidean War, the Ptolemaic navy succeeded in blockading Macedonia and containing its imperial ambitions to mainland Greece.