Now after this he built a wall without the city of David, on the west side of Gihon, in the valley, even to the entering in at the fish gate, and compassed about Ophel, and raised it up a very great height, and put captains of war in all the fenced cities of Judah.
He built a wall without the city ... on the west side of Gihon ... even to the entering in at the fish gate.
'The well-ascertained position of the Fish Gate shows that the Valley of Gihon could be no other than that leading northwest of Damascus Gate, and gently descending southward, uniting with the Tyropoeon at the northeast corner of mount Zion, where the latter turns at right angles and runs toward Siloam. The wall thus built by Manasseh, on the west side of the valley of Gihon, would extend from the vicinity of the northeast corner of the wall of Zion in a northerly direction, until it crossed over the valley to form a junction with the outer wall at the Trench of Antonia, precisely in the quarter where the temple would be most easily assailed' outer wall at the Trench of Antonia, precisely in the quarter where the temple would be most easily assailed' (Barclay).
The necessity for Manasseh's raising this fortification was this: Psammeticus having established himself on the throne of Egypt, seven years after Manasseh's restoration, proceeded to extend his conquests, and having laid siege to Ashdod, which lasted twenty-nine years, war ensued between the Egyptians and the Assyrians. In consequence of this, Manasseh, as vassal and lieutenant of the Assyrian sovereign, was obliged to increase the fortifications of Jerusalem.