In the fourteenth year of King Hezekiah's reign, the narrative shifts sharply from visions and warnings to a historical account of the Assyrian military campaign in Judah. This historical record is included within the prophetic book to demonstrate exactly how the earlier prophecies regarding the downfall of Assyria and the rescue of Hezekiah were completely fulfilled [שד״ל, אברבנאל]. While these same events are recorded in the Books of Kings and Chronicles, the slight variations in wording do not alter the core meaning, as words simply serve as vessels for the underlying message [אבן עזרא, רד״ק]. The primary distinction lies in their purpose: the Book of Kings aims to document the life of the monarch, whereas this account focuses entirely on the realization of prophecy [אברבנאל]. In fact, the record found in the Book of Kings is essentially an abridged version copied directly from the original writings of Isaiah [שד״ל].
The roots of this conflict trace back to Hezekiah's father, Ahaz, who had lived under subjugation to the Assyrian empire. Upon his father's death, Hezekiah rebelled and ended this submission. In response, Sennacherib, identified as the same Shalmaneser who had destroyed Samaria and exiled the Israelites eight years prior, marched against Judah. Filled with arrogance, he was confident he could destroy Jerusalem just as he had crushed Samaria [אברבנאל].
The full sequence of events emerges when combining the various biblical accounts. As the Assyrian forces began conquering the Judean cities, Hezekiah attempted to negotiate peace by sending a heavy tribute of silver and gold. His actual goal, however, was to buy enough time to prepare Jerusalem for war by fortifying its walls and sealing off the local water springs. Once Sennacherib received the payment, he viewed these defensive preparations as a violation of their agreement. Reacting with malice, he renewed his assault on Judah, dispatching his commander Rabshakeh with a massive army toward Jerusalem [מלבי״ם, אברבנאל]. A different approach suggests that Sennacherib did return to his homeland after receiving the initial payment, but launched a second attack when Hezekiah refused to continue paying the tribute on an annual basis [אברבנאל].
The Assyrian advance targeted the fortified, powerful cities of Judah, capturing and taking full control of them [מצודת ציון]. The unfortified towns simply surrendered on their own without a fight [מצודת ציון, אברבנאל]. Although the campaign was vast, not every single city fell immediately, as strongholds like Lachish and Libnah initially remained unconquered [שד״ל].