Sennacherib was an Assyrian king who is best known in the Bible for losing 185,000 soldiers in his failed attempt to conquer Jerusalem. He was a contemporary of King Hezekiah of the Kingdom of Judah, the prophet Isaiah and the Egyptian Pharaoh Tirhaqa, also mentioned in the Bible.
He ruled for some 24 years, 705 - 681 BC, following a 17-year reign by his father Sargon II. He is the second ruler in the Sargonid dynasty. He was assassinated by two of his sons, and was succeeded by another son, Esarhaddon.
His notable achievements include moving the capital from Dur-Sharrukin (Fortress of Sargon), built by his father Sargon II, to Nineveh, a vast building project. He conducted a number of successful military campaigns. He also destroyed the city of Babylon in 689 BC after repeated rebellions, one of which had resulted in the execution of his vassal king, one of his sons.
The defeated king of one of the Babylonian rebellions was Marduk-apla-iddina, referred to in 2 Kings 20 and Isaiah 39 as Merodach Baladan.
Sennacherib invaded the Kingdom of Judah (also known as the southern tribes) after his predecessors, Tiglath-Pileser III, Shalmaneser V and Sargon II, wiped out the Kingdom of Israel (also known as the northern tribes). The attack was in response to Hezekiah’s rebellion against Assyria, and his subsequent reliance on Egypt for help.
In Isaiah 8:5-8, God tells the prophet Isaiah that because the people of the Kingdom of Judah have rejected him, he will bring the mighty Assyrians, depicted as flood waters, against them.
Sennacherib would fulfill this prophecy by conquering 46 towns, fortresses and fortified cities including the fortified city of Lachish, second in size only to Jerusalem. The prophet Micah warned the inhabitants of Lachish to flee the city, blaming them for inducing the nearby city of Jerusalem, and hence the Kingdom of Judah, to sin against God; see Micah 1:13.
The Assyrian victory over Lachish was depicted in a set of wall reliefs that first decorated Sennacherib’s palace in Nineveh and is now in the British Museum. Some of the scenes are quite gruesome.
After this successful battle, Sennacherib would lay siege to Jerusalem, the details of which are told in 2 Kings 18-19, Isaiah 36-37 and 2 Chronicles 32. The texts in 2 Kings and Isaiah are nearly identical but 2 Kings has a few more details. There is a debate over which account was written first.
While Sennacherib would boast, "Himself {Hezekiah] I made a prisoner in Jerusalem, his royal residence, like a bird in a cage”, he never entered Jerusalem. This statement is recorded on a six-sided baked clay document, the Taylor prism, which is also in the British Museum.
The reason for Sennacherib’s departure is unclear; the Bible implies that the loss of 185,000 men was the cause but it could have been another rebellion by Marduk-apla-iddina in Babylon that pulled him away. Also, 2 Kings 18 records that Hezekiah made a huge tribute payment to Sennacherib.
In 2 Kings 19:7, the prophet Isaiah tells King Hezekiah that Sennacherib will be cut down by the sword, which eventually happened in 681 BC.
https://www.britishmuseum.org/collection/object/W_1847-0702-1-2
Sennacherib is most likely the young man on the right, facing his father, King Sargon II. As the crown prince, Sennacherib would succeed his father on the throne.
Also note the common Assyrian artistic practice of placing the superior person on the left, facing right, and the subordinate person on the right, facing left.
https://artsandculture.google.com/streetview/british-museum/AwEp68JO4NECkQ?sv_lng=-0.1276883751522462&sv_lat=51.51901289418876&sv_h=234.10116169646963&sv_p=1.376766755242798&sv_pid=PDvUT3E-UQc3jCudWThZ8Q&sv_z=1.0000000000000002
Famous English poet Lord Byron wrote a dramatic poem in 1815, The Destruction of Sennacherib, depicting Sennacherib’s loss on the battlefield:
https://www.poetrybyheart.org.uk/poems/the-destruction-of-sennacherib/