How did Themistocles manage to convince the Greeks to build a navy?

A huge threat from the Persians was brewing, the Greeks feared the invasion of Xerxes into their territories. Themistocles, being a good politician and competent strategist, convinced the inhabitants of Athens to fully strengthen and modernize their defenses – this required the immediate construction of a Greek navy. Ultimately, the Persians attacked Greece, the fears were not in vain and Themistocles was completely right. In a decisive battle at sea, the Athenians defeated Xerxes’ fleet and left their heroic imprint on the pages of history.