Jeremiah 39:2

And in the eleventh year of Zedekiah, in the fourth month, the ninth day of the month, the city was broken up, the enemies gained an entry into the city by battering down a part of the wall. The siege thus lasted eighteen months, if we except the suspension of it caused by the coming of Pharaoh-hophrah. Nebuchadnezzar was present at the beginning of the siege, but was in Riblah at its close.