The kingdom known for its powerful navy and dominance in the Mediterranean around 400 BC was Carthage. Located in present-day Tunisia, Carthage was a major trading empire and exerted considerable influence over the western Mediterranean. Its formidable navy was crucial for trade protection and military expansion, allowing Carthage to engage in conflicts such as the Punic Wars against Rome. Carthage's advanced maritime technology, strategic location, and wealth from commerce contributed to its prominence, making it a key player in ancient geopolitics. However, its eventual defeat by Rome would lead to its downfall.