The Siege of Jerusalem and the campaign of Sennacherib are recorded on the Oriental Institute's Prism of Sennacherib. Further references to the campaign (particularly the siege of Lachich) are found on the palace reliefs.
Source: James Pritchard, ed., Ancient Near Eastern texts relating to the Old Testament (Princeton, 1969) pp. 287-88
(ii - iii 49) In my third campaign I marched against Hatti. Luli, king of Sidon, whom the terror-inspiring glamor of my lordship had overwhelmed, fled far overseas and perished. The awe-inspiring splendor of the "Weapon" of Ashur, my lord, overwhelmed his strong cities (such as) Great Sidon, Little Sidon, Bit-Zitti, Zaribtu, Mahal liba, Ushu (i.e. the mainland settlement of Tyre), Akzib (and) Akko, (all) his fortress cities, walled (and well) provided with feed and water for his garrisons, and they bowed in submission to my feet.
I installed Ethba'al (Tuba'lu) upon the throne to be their king and imposed upon him tribute (due) to me (as his) overlord (to be paid) annually without interruption. As to all the kings of Amurru - Menahem (Mi-inhi-im-mu) from Samsimuruna, Tuba'lu from Sidon, Abdili'ti from Arvad, Urumilki from Byblos, Mitinti from Ashdod, Buduili from Beth-Ammon, Kammusunadbi from Moab (and) Aiarammu from Edom, they brought sumptuous gifts (igisu) and fourfold their heavy tamartu-presents to me and kissed my feet.
Sidqia, however, king of Ashkelon, who did not bow to my yoke, I deported and sent to Assyria, his family gods, himself, his wife, his children, his brothers, all the male descendants of his family. I set Sharruludari, son of Rukibtu, their former king, over the inhabitants of Ashkelon and imposed upon him the payment of tribute (and of) katru-presents (due) to me (as) overlord and he (now) pulls the straps (of my yoke)!
In the continuation of my campaign I besieged Beth Dagon, Joppa, Banai-Barqa, Azuru, cities belonging to Sidqia who did not bow to my feet quickly (enough); I conquered (them) and carried their spoils away.
The officials, the patricians and the (common) people of Ekron, who had thrown Padi, their king, into fetters (because he was) loyal to (his) solemn oath (sworn) by the god Ashur, and had handed him over to Hezekiah, the Jew (Ha-za-qi-(i)a-u ame~la-u'-da-ai) (and) he (Hezekiah) held him in prison, unlawfully, as if he (Padi) be an enemy had become afraid and had called (for help) upon the kings of Egypt (Mu,s(u)ri) (and) the bowmen, the chariot(-corps) and the cavalry of the king of Ethiopia (Meluhha), an army beyond counting and they (actually) had come to their assistance.
In the plain of Eltekeh (A1-ta-qu-u), their battle lines were drawn up against me and they sharpened their weapons. Upon a trust(-inspiring) oracle (given) by Ashur, my lord, I fought with them and inflicted a defeat upon them. In the middle of the battle, I personally captured alive the Egyptian charioteers with the(ir) princes and (also) the charioteers of the king of Ethiopia. I besieged Eltekeh (and) Timnah (Ta-amna-a), conquered (them) and carried their spoils away. I assaulted Ekron and killed the officials and patricians who had committed the crime and hung their bodies on poles surrounding the city. The (common) citizens who were guilty of minor crimes, I considered prisoners of war. The rest of them, those who were not of crimes and misbehavior, I released. I made Padi, their king, come from Jerusalem (Ur-sa-li-im-mu) and set him as their lord on the throne, imposing upon him the tribute (due) to me (as) overlord.
As to Hezekiah, the Jew, he did not submit to my yoke, I laid siege to 46 of his strong cities, walled forts and to the countless small villages in their vicinity, and conquered (them) by means of well-stamped (earth-)ramps and battering-rams brought (thus) near (to the walls) (combined with) the attack by foot soldiers, (using) mines, breeches as well as sapper work. I drove out (of them) 200,150 people, young and old, male and female, horses, mules, donkeys, camels, big and small cattle beyond counting, and considered (them) booty. Himself I made a prisoner in Jerusalem, his royal residence, like a bird in a cage. I surrounded him with earthwork in order to molest those who were his city's gate. His towns which I had plundered, I took away from his country and gave them (over) to Mitinti, king of Ashdod, Padi, king of Ekron, and Sillibel, king of Gaza.
Thus I reduced his country, but I still increased the tribute and the katru -presents (due) to me (as his) overlord which I imposed (later) upon him beyond the former tribute, to be delivered annually. Hezekiah himself, whom the terror-inspiring splendor of my lordship had overwhelmed and whose irregular and elite troops which he had brought into Jerusalem, his royal residence, in order to strengthen (it), had deserted him, did send me, later, to Nineveh, my lordly city, together with 30 talents of gold, 800 talents of silver, precious stones, antimony, large cuts of red stone, couches (inlaid) with ivory, nimedu-chairs (inlaid) with ivory, elephant-hides, ebony-wood, boxwood (and) all kinds of valuable treasures, his (own) daughters, concubines, male and female musicians. In order to deliver the tribute to do obeisance as a slave he sent his (personal) messenger.