Who was Sennacherib, the king of Assyria, in the Bible?

TL;DR:

Sennacherib, the King of Assyria, was a proud king who mocked Yahweh. God miraculously defeated Sennacherib, yet his pride kept him from turning to God.

Sennacherib threatened to conquer Jerusalem, mocking Yahweh's ability to protect the city, prompting King Hezekiah to seek God's help through prayer and the prophet Isaiah. God assured Hezekiah that Jerusalem would be saved. He sent an angel who killed 185,000 Assyrian soldiers, causing Sennacherib to retreat. Despite this amazing defeat, Sennacherib did not turn to worship Yahweh and was eventually killed by his own sons while worshiping his god. The people of Judah recognized God's power and brought gifts to the Lord in Jerusalem. This account highlights God's sovereignty and the importance of seeking Him in prayer.

from the old testament

In the Bible, we hear only of Sennacherib's threat to invade Jerusalem, how God protected the city, and about Sennacherib's eventual demise. This account can be found in 2 Kings 18:13—19:37, Isaiah 36—37, and 2 Chronicles 32.
Sennacherib sent his servants to instruct King Hezekiah and the people of Jerusalem to surrender to him in order to avoid being conquered like the numerous other cities and people groups Sennacherib had already defeated (2 Kings 18:13–35). In this message, Sennacherib posited that Yahweh, the God of the Israelites, would not be able to protect Jerusalem just like the false gods of other cities did not protect those cities from Assyrian conquest (2 Kings 18:32–35).
When Hezekiah heard this threat to the city and the insult to God, he tore his clothes and went to the temple. He also sent word to the prophet Isaiah (2 Kings 19:1–4), who responded with an encouraging word from the Lord (2 Kings 19:5–7).
Sennacherib again sent messengers to Hezekiah warning him against trusting the Lord. Hezekiah spread the letter out before the Lord and prayed. Both he and Isaiah cried out in prayer (2 Chronicles 32:20).
Isaiah was given a word from the Lord about Sennacherib, highlighting Sennacherib's pride and mockery of God. God said that it was Him who had determined Sennacherib's previous conquests and that "Because you [Sennacherib] have raged against me [God] and your complacency has come into my ears, I will put my hook in your nose and my bit in your mouth, and I will turn you back on the way by which you came" (2 Kings 19:28).
Isaiah was given word that the Lord would rescue Jerusalem so that Sennacherib would never enter the city or even build a siege ramp against it (2 Kings 19:32–34). In fact, "that night the angel of the LORD went out and struck down 185,000 in the camp of the Assyrians. And when people arose early in the morning, behold, these were all dead bodies. Then Sennacherib king of Assyria departed and went home and lived at Nineveh" (2 Kings 19:35–36).
God did, indeed, protect Jerusalem and thereby protect His reputation as the most powerful and only true God who is sovereign over all earthly rulers and any false gods people might be tempted to trust in or worship. Unfortunately, even this defeat by the one true God was not enough to turn Sennacherib from his worship of false idols. Isaiah 37:38a records, "And as he [Sennacherib] was worshiping in the house of Nisroch his god, Adrammelech and Sharezer, his sons, struck him down with the sword."
While Sennacherib was not convinced of Yahweh's worthiness to be worshiped for protecting Jerusalem, the people in Judah certainly recognized God's mighty act. Second Chronicles 32:22–23a states, "So the LORD saved Hezekiah and the inhabitants of Jerusalem from the hand of Sennacherib king of Assyria and from the hand of all his enemies, and he provided for them on every side. And many brought gifts to the LORD to Jerusalem."

from the new testament

Sennacherib is only mentioned in the Old Testament.

implications for today

When Hezekiah had prayed for deliverance from Sennacherib, he did not ask for the sake of the comfort and ease of his people, but rather he appealed to God on behalf of God's reputation. He said, "So now, O LORD our God, save us, please, from his hand, that all the kingdoms of the earth may know that you, O LORD, are God alone" (2 Kings 19:19). Hezekiah wanted God to get the glory of rescuing Jerusalem especially in contrast to the false gods who could not rescue previously conquered cities. When God responded, He said, "For I will defend this city to save it, for my own sake and for the sake of my servant David" (2 Kings 19:34). God defended Jerusalem against the proud Sennacherib to display His own strength and glory as well as His faithfulness in keeping His promises.

What a challenge—that when we pray it should be not for our own comfort and ease, but rather for God to display His glory, strength, and faithfulness in our lives so that others may know Him better! And what a comfort to know that Yahweh is the one true God sovereign over all earthly rulers able to deliver us in our time of need!

understand

Sennacherib, king of Assyria, threatened to conquer Jerusalem, mocking the ability of Yahweh to protect the city, just as the gods of other conquered peoples had failed to protect them.
In response to Sennacherib's threat, King Hezekiah sought God's help, praying earnestly alongside the prophet Isaiah. God assured them that He would defend Jerusalem. Consequently, God sent an angel who killed 185,000 Assyrian soldiers, leading to Sennacherib's retreat.
Despite the miraculous defeat, Sennacherib did not turn to worship Yahweh and was eventually killed by his own sons while worshiping his god Nisroch.

reflect

How do you respond when faced with threats or challenges that seem insurmountable? Do you turn to God in prayer like Hezekiah, or do you rely on your own strength?
In what ways might pride be preventing you, like Sennacherib, from acknowledging God's power and seeking His help in your life?
How can you ensure that your prayers focus on God's glory and not just your own comfort and ease?

engage

From history: Sennacherib was the king of Assyria who reigned from 705 BC to 681 BC and threatened Jerusalem while Hezekiah was king of Judah. Sennacherib is remembered as a violent and brutal king. He conquered many cities and, as was the Assyrian custom, then deported conquered peoples throughout the kingdom in order to annihilate their distinct cultures. He installed his son to rule in the city of Babylon, but the Babylonians rebelled and killed his son. In retaliation, Sennacherib completely destroyed Babylon in 689 BC. He is also remembered for moving the capital of Assyria from Nimrud to Nineveh and for constructing walls, temples, and a palace garden there during the city's renovation and expansion to make it a worthy capital. After the death of his son in Babylon, Sennacherib announced that one of his younger sons, Esarhaddon, was to succeed him as king, which angered two of his older sons. Those older sons then murdered Sennacherib while he was worshiping in the temple of the false god Nisroch, thereby ending his reign prematurely. The two older sons then fled, and Esarhaddon was installed as the next king just as Sennacherib had prescribed.
How does the account of Sennacherib's defeat illustrate God's sovereignty and power over earthly rulers and false gods?
Why do people like Sennacherib continue to worship false gods despite evidence God gives to know Him? How can we guard against similar pride and stubbornness in our own spiritual journeys?