History of the Peloponnesian War

Themistocles, moreover, persuaded them also to finish the walls of the Peiraeus, a beginning of which had been made during the year in which he was archon of the Athenians; for he considered that the Peiraeus with its three natural harbours[*](The Peiraeus, here in widest sense, is the peninsula, the heart of which is the steep height of Munychia, from which it stretches into the sea like an indented leaf, forming three natural basins—the Peiraeus, Zea, Munychia.) was a fine site to develop and that to have become a nation of seamen would be a great advantage to the Athenians themselves, with a view to their acquisition of power—

indeed it was he who first dared declare that they must apply themselves to the sea—and so he immediately took the first steps in this undertaking.[*](Others render: immediately began to help them to lay the foundation of their empire.)