History of the Peloponnesian War

For he was the first who ventured to tell them that they must apply closely to the sea;

and he began immediately to assist in paving the way for their empire. It was by his advice that they built the walls of that thickness which is still seen round the Piraeus; for two waggons meeting each other brought up the stones. And in the inside there was neither rubble nor mortar, but large and square-cut stones wrought together, cramped on the outside with iron and lead. But only about half of the height he intended was finished.

For he wished by their great dimensions and thickness to keep off the attacks of their enemies; and thought that the protection of a few, and those the least efficient troops, would be sufficient, while the rest would go on board their ships.

For to the navy he paid the greatest attention; seeing, I suppose, that the approach of the king's forces against them was easier by sea than by land: and he considered the Piraeus more serviceable than the upper city, and often advised the Athenians, in case of their ever being hard pressed by land, to go down into it, and defy the world with their navy.

Thus then the Athenians were enclosed with walls, and began to furnish themselves with other buildings immediately after the retreat of the Medes.

Now Pausanias, the son of Cleombrotus, was sent out from Lacedaemon as general of the Greeks with twenty ships from the Peloponnese; there sailed with him also the Athenians with thirty ships, and a large number of the other allies.

And they made an expedition against Cyprus, and subdued the greater part of it; and afterwards against Byzantium, of which the Medes were in possession, and reduced it during this period of his command.