Assyrians Were Ancient Masters of the Siege
Siege warfare became a highly specialized technique in the Neo-Assyrian period and many of the skills developed by the Assyrians were subsequently adopted, improved upon, and expanded by later imperial powers including the Romans. Against the moats and ramparts of the well-fortified garrisons the Assyrian engineers brought a variety of engines and skills. There were the enclosed battering rams on wheels, in effect primitive tanks, with archers ensconced in turrets on top to pick off defenders on the wall who would attempt to burn the machine with torches or dislodge the battering rams with ‘wolves’, looped chains lowered from the walls. As for scaling techniques, in addition to using ladders, earthen ramps were sometimes heaped up against the wall for battering rams to roll up and demolish the upper defences and allow the infantry to rush up and over. The Assyrians also used sappers to burrow under or through the walls and fires were set with torches at wooden gates. Engineers engaged in these various activities were under constant threat from the defenders who shot arrows and spears at them, dropped rocks and scalding liquid. Cover was provided by the archers who took up strategic positions with their shield-bearers.
If the initial attempts at taking a city by siege failed, the Assyrians usually withdrew, but not before ravaging the surrounding countryside, burning and destroying crops, trees and houses. Only on occasion would they settle down for a long siege. When they did this, they stationed small groups of men in redoubts and siege towers near the wall, particularly near the gates, in order to prevent any traffic in or out of the city and to warn of any planned sortie from the gates. Once ensconced, the Assyrians were willing to wait many months or even a year or more, until the starved inhabitants capitulated.
— The Cambridge Ancient History, volume III, part 2, p. 220