History of the Peloponnesian War

The city wall on the isthmus side[*](The wall on the Isthmus side of the Potideans is the τεῖχος of Thuc. 1.62.6; the wall to Pallene is that mentioned in Thuc. 1.56.2 as τὸ ἐς παλλήνων τεῖχος.) the Athenians immediately cut off by a transverse wall and set a guard there, but the wall toward Pallene was not shut off.[*](The investment of Potidaea was effected by walling off first the northern and then also the southern city wall by a blockading wall; on the west and east, where the city extended to the sea, the blockade was made with ships.) For they thought their numbers were insufficient to maintain a garrison on the isthmus and also to cross over to Pallene and build a wall there too, fearing that, if they divided their forces, the Potidaeans and their allies would attack them.

Afterwards, when the Athenians at home learned that Pallene was not blockaded, they sent sixteen hundred of their own hoplites under the command of Phormio son of Asopius; and he, when he arrived at Pallene, making Aphytis his base, brought his army to Potidaea, marching leisurely and ravaging the country at the same time. And as no one came out against him to give battle he built a wall to blockade the Pallene wall.

And so Potidaea was at length in a state of siege, which was prosecuted vigorously on both sides of it as well as by sea, where a fleet blockaded it.