He continued to advocate for a strong Athenian Navy, and in 483 BC he persuaded the Athenians to build a fleet of 200 triremes; these proved crucial in the forthcoming conflict with Persia. During the second invasion, he effectively commanded the Greek allied navy at the battles of Artemisium and Salamis in 480 BC
Themistocles was able to persuade the Athenians to build a whole fleet of battleships called triremes. Triremes were built with a bronze ram mounted on the front that was used to ram enemy ships below the waterline, causing them to sink. The new ships were powered by three rows of oarsmen on each side who together could reach speeds of about five miles an hour, a very good speed for a battle ship. The trireme became a major asset to the Athenians, allowing them to gain control by sea of much of the land around the Mediterranean and the Black Seas.
